Answers from church history on today's questions
What Christian writers said, from about AD 155 to 1930.
83 passages · 21 writers · 8 centuries
Of the 83 passages here from 21 writers, 71 state a position on whether a Christian may take an oath and 12 mention oaths in passing. Calvin, Hodge, the Heidelberg Catechism, the Thirty-Nine Articles, and the Westminster Confession hold that a truthful oath taken by God's name, when the magistrate or necessity requires it, is lawful, and Luther, Calvin, and Hodge cite the law, the prophets, and the apostles as warrant. Aquinas also holds that oaths are lawful, but allows oaths by creatures that reflect God's truth. Wesley, Barnes, Robertson, and Jamieson, Fausset, and Brown read “Swear not at all” as applying to oaths in ordinary speech, not to oaths before a magistrate, while Maclaren argues that the principle behind the command is hard to keep from judicial oaths. Basil, Chrysostom, and the Constitutions of the Holy Apostles (about AD 375) read the command as a call to avoid oaths, and Chrysostom and Augustine add that frequent swearing leads to perjury. The record has no Quaker or Anabaptist writer; their reading of “Swear not at all” appears only as Calvin and Jamieson, Fausset, and Brown describe it.
15 passages · 12 writers · 300s to 1900s
Writers differ on whether Matthew 5:34 and James 5:12 forbid every oath or only oaths in ordinary speech.
And indeed this very thing, the oath, was ordained of old for this cause, that they might not swear by the idols. … “What then,” it may be said, “is not swearing of the evil one?” Yes, indeed it is altogether of the evil one; that is, now, after so high a rule of self-restraint; but then not so.
John Chrysostom, The Homilies of St. John Chrysostom 20
And yet the Lord says, “Swear not at all:” for He hath not granted license thereof to persons writing. Howbeit, because to pronounce Paul guilty of violating the commandment, especially in Epistles written and sent forth for the spiritual life and salvation of the nations, were an impiety, we must understand that word which is set down, “At all,” to be set down for this purpose, that as much as in thee lies, thou affect not, love not, nor as though it were for a good thing, with any delight desire, an oath.
Augustine of Hippo, On Lying 28
Reply to Objection 1: Jerome, commenting on Mat. 5:34, says: "Observe that our Saviour forbade us to swear, not by God, but by heaven and earth. For it is known that the Jews have this most evil custom of swearing by the elements." Yet this answer does not suffice, because James adds, "nor by any other oath." Wherefore we must reply that, as Augustine states (De Mendacio xv), "when the Apostle employs an oath in his epistles, he shows how we are to understand the saying, 'I say to you, not to swear at all'; lest, to wit, swearing lead us to swear easily and from swearing easily, we contract the habit, and, from swearing habitually, we fall into perjury.
Thomas Aquinas, Summa Theologica II-II.Q89.A2
It hence appears that it was not Christ’s design (as the superstitious Anabaptists dream) to abolish oaths altogether, but on the contrary to call attention to the due observance of the law; and the law, allowing an oath, only condemns perjury and needless swearing. If then we would use an oath aright, let us imitate the seriousness and the reverent manner exhibited by the Apostles; and that you may understand what it is, know that God is so called as a witness, that he is also appealed to as an avenger, in case we deceive; which Paul expresses elsewhere in these words, “God is a witness to my soul.” ( 2 Corinthians 1:23 .)
John Calvin, Commentary on Romans 1.3
Christ, therefore, meant nothing more than this, that all oaths are unlawful, which in any way abuse and profane the sacred name of God, for which they ought to have had the effect of producing a deeper reverence.
John Calvin, Harmony of the Evangelists, Vol. 1 5.48
26. The Anabaptists, not content with this moderate use of oaths, condemn all, without exception, on the ground of our Saviour’s general prohibition, “I say unto you, Swear not at all:” “Let your speech be Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil,” (Mt. 5:34; James 5:12). In this way, they inconsiderately make a stumbling-stone of Christ, setting him in opposition to the Father, as if he had descended into the world to annul his decrees. In the Law, the Almighty not only permits an oath as a thing that is lawful (this were amply sufficient), but, in a case of necessity, actually commands it (Exod. 22:11).
John Calvin, Institutes of the Christian Religion II.8
The reason is observable; For whatsoever is more than these cometh of evil, though it do not amount to the iniquity of an oath. It comes ek tou Diabolou ; so an ancient copy has it: it comes from the Devil, the evil one; it comes from the corruption of men's nature, from passion and vehemence; from a reigning vanity in the mind, and a contempt of sacred things: it comes from that deceitfulness which is in men, All men are liars; therefore men use these protestations, because they are distrustful one of another, and think they cannot be believed without them. Note, Christians should, for the credit of their religion, avoid not only that which is in itself evil, but that which cometh of evil, and has the appearance of it. That may be suspected as a bad thing, which comes from a bad cause. An oath is physic, which supposes a disease.
Matthew Henry, Commentary on Matthew 5.7
The apostle here particularly forbids these oaths, as well as all swearing in common conversation. … But he does not forbid the taking a solemn oath before a magistrate.
John Wesley, Notes on the Bible 20.5
The command "to swear by His Name" is not inconsistent with the Lord's injunction Mat 5:34, "Swear not at all." Moses refers to legal swearing, our Lord to swearing in common conversation.
Albert Barnes, Notes on the Bible Deuteronomy 6:10
Common swearing, or thoughtless oaths in common talk. 534. Are not such oaths specially forbidden in holy Scripture? The Saviour says: I say unto you, Swear not at all, but let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil.
Philaret of Moscow, The Longer Catechism of the Orthodox, Catholic, Eastern Church q. 532–535
But I say unto you, Swear not at all—That this was meant to condemn swearing of every kind and on every occasion—as the Society of Friends and some other ultra-moralists allege—is not for a moment to be thought. For even Jehovah is said once and again to have sworn by Himself; and our Lord certainly answered upon oath to a question put to Him by the high priest; and the apostle several times, and in the most solemn language, takes God to witness that he spoke and wrote the truth; and it is inconceivable that our Lord should here have quoted the precept about not forswearing ourselves, but performing to the Lord our oaths, only to give a precept of His own directly in the teeth of it. Evidently, it is swearing in common intercourse and on frivolous occasions that is here meant.
Robert Jamieson, A.R. Fausset, and David Brown, Commentary Critical and Explanatory on the Whole Bible Matthew 5
Seeing, then, that an oath is an act of worship; that it is enjoined on suitable occasions; that our Lord himself submitted to be put upon his oath; and that the Apostles did not hesitate to call God to witness to the truth of what they said; we cannot admit that Christ intended to pronounce all oaths unlawful, when he said, as recorded in Matthew v. 34, “Swear not at all.” This would be to suppose that Scripture can contradict Scripture, and that Christ’s conduct did not conform to his precepts.
Charles Hodge, Systematic Theology III.19.7
The oaths specified are all colloquial, which were and are continually and offensively mingled with common speech in the East. Nowhere are there such habitual liars, and nowhere are there so many oaths. Every traveller there knows that, and sees how true is Christ’s filiation of the custom of swearing from the custom of falsehood. But these poisonous weeds of speech not only tended to degrade plain veracity in the popular mind, but were themselves parents of immoral evasions, for it was the teaching of some Rabbis, at all events, that an oath ‘by heaven’ or ‘by earth’ or ‘by Jerusalem’ or ‘by my head’ did not bind. That further relaxation of the obligation of truthfulness was grounded on the words quoted in verse 33, for, said the immoral quibblers, ‘it is “thine oaths to the Lord” that thou “shalt perform,” and for these others you may do as you like’ Therefore our Lord insists that every oath, even these mutilated, colloquial ones which avoid His name, is in essence an appeal to God, and has no sense unless it is.
Alexander Maclaren, Ezekiel, Daniel and the Minor Prophets; and Matthew Chaps. I to VIII 2.25
It must be fully admitted that there is little in common between such pieces of senseless profanity as these oaths, or the modern equivalents which pollute so many lips to-day, and the oath administered in a court of justice, and it may further be allowed weight that Jesus does not specifically prohibit the oath ‘by the Lord,’ but it is difficult to see how the principles on which He condemns are to be kept from touching even judicial oaths. For they, too, are administered on the ground of the false idea that they add to the obligation of veracity, and give a guarantee of truthfulness which a simple affirmation does not give. Nor can any one, who knows the perfunctory formality and indifference with which such oaths are administered and taken, and what a farce ‘kissing the book’ has become, doubt that even judicial oaths tend to weaken the popular conception of the sin of a lie and the reliance to be placed upon the simple ‘Yea, yea; Nay, nay.’
Alexander Maclaren, Ezekiel, Daniel and the Minor Prophets; and Matthew Chaps. I to VIII 2.25
Certainly Jesus does not prohibit oaths in a court of justice for he himself answered Caiaphas on oath. Paul made solemn appeals to God (1Th 5:27; 1Co 15:31 ). Jesus prohibits all forms of profanity.
A.T. Robertson, Word Pictures in the New Testament 2.5
7 passages · 3 writers · 1500s to 1800s
Writers define an oath as calling God to witness and, in many cases, as an act of religious worship.
The act of solemnly calling upon God to witness and judge what we say, is one part of divine worship: hence an oath, by the figure of speech called synecdoche, is made to signify the profession of religion in general. We are not to imagine from this that God reckons all those to be his servants who make mention of his name. Many take it into their lips only to profane it by the grossest perjury; others outrage or slight it by entering into trifling and unnecessary oaths; and hypocrites are chargeable with wickedly abusing it. But those whom David refers to are such as swear by the Lord, considerately and with reverence, and whose hearts respond to what they declare.
John Calvin, Commentary on the Psalms, Vol. 2 63.3
There is a manifest synecdoche in this Commandment; for in order that God may procure for His name its due reverence, He forbids its being taken in vain, especially in oaths. Whence we infer on the other hand an affirmative commandment, that every oath should be a testimony of true piety, whereby the majesty of God Himself should obtain its proper glory. … We shall soon see that to swear by God’s name is a species or part of religious worship, and this is manifest too from the words of Isaiah 45:23 ; for when he predicts that all nations shall devote themselves to pure religion, he thus speaks, “As I live, saith the Lord, every knee shall bow to me, and every tongue shall swear by me.”
John Calvin, Harmony of the Law, Vol. 2 3.1.1
It ought also to be observed, that those things which belong to the worship of God ought not to be applied to any other purpose, and therefore it is a profanation of an oath if we swear by any other. … Let it likewise be observed with what solemnity oaths should be made; for if by swearing we profess to worship God, we ought never to engage in it but with fear and reverence.
John Calvin, Commentary on Isaiah, Vol. 2 19.1
An oath, then, is calling God to witness that what we say is true. Execrations being manifestly insulting to God, are unworthy of being classed among oaths. That an oath, when duly taken, is a species of divine worship, appears from many passages of Scripture, as when Isaiah prophesies of the admission of the Assyrians and Egyptians to a participation in the covenant, he says, “In that day shall five cities in the land of Egypt speak the language of Canaan, and swear to the Lord of hosts,” (Isaiah 19:18).
John Calvin, Institutes of the Christian Religion II.8
By appealing to the name of the Lord, and calling him to witness, we are justly said to declare our own religious veneration of him. For we thus acknowledge that he is eternal and unchangeable truth, inasmuch as we not only call upon him, in preference to others, as a fit witness to the truth, but as its only assertor, able to bring hidden things to light, a discerner of the hearts. When human testimony fails, we appeal to God as witness, especially when the matter to be proved lies hid in the conscience.
John Calvin, Institutes of the Christian Religion II.8
1. A lawful oath is a part of religious worship, wherein, upon just occasion, the person swearing solemnly calleth God to witness what he asserteth, or promiseth, and to judge him according to the truth or falsehood of what he sweareth.
Westminster Assembly, Westminster Confession of Faith 22.1
The command not to call upon God to confirm a lie, cannot be considered as forbidding us to call upon Him to confirm the truth. And such is the general nature of an oath. … An oath, therefore, is in its nature an act of worship.
Charles Hodge, Systematic Theology III.19.7
7 passages · 3 writers · 1500s to 1700s
Writers cite the commandments, the law, the prophets, and the apostles as evidence that oaths are permitted.
Hence it is a natural inference, since using the holy name for falsehood or wickedness is here forbidden, that we are, on the other hand, commanded to employ it for truth and for all good, as when one swears truly where there is need and it is demanded.
Martin Luther, Luther's Large Catechism 11.1
But it was expedient, as I have said, in order that his oath might attain more credit, that Paul should declare his piety towards God; for perjury is a sport to the ungodly, while the pious dread it more than a thousand deaths; inasmuch as it cannot be, but that where there is a real fear of God, there must be also a reverence for his name. It is then the same thing, as though Paul had said, that he knew how much sacredness and sincerity belonged to an oath, and that he did not rashly appeal to God as a witness, as the profane are wont to do. And thus, by his own example, he teaches us, that whenever we swear, we ought to give such evidence of piety, that the name of God, which we use in our declarations, may retain its sacredness.
John Calvin, Commentary on Romans 1.3
But here in passing, two things are to be noticed, — that we are to swear by God’s name when necessity requires, and that Christians are allowed to make an oath, because it is a lawful remedy for removing contentions. God in express words bids us to swear by his name; if other names are blended with it, the oath is profaned.
John Calvin, Commentary on Hebrews 6.5
For it is a singular favor on the part of God, that he allows us to take his name when there is any controversy among us, and when a confirmation is necessary. As then we thus receive through kindness the name of God, it is surely a great favor; for how great is the sanctity of that name, though it serves even earthly concerns? God then does so far accommodate himself to us, that it is lawful for us to swear by his name. Hence a greater seriousness ought to be observed by us in oaths, so that no one should dare to interpose an oath except when necessity requires; and we should also especially take heed lest God be called a witness to what is false.
John Calvin, Commentary on Habakkuk, Zephaniah, and Haggai Zephaniah 1.5
Further, this passage teaches us, as it has been said, that an oath may be lawfully used by Christians; and this ought to be particularly observed, on account of fanatical men who are disposed to abrogate the practice of solemn swearing which God has prescribed in his Law. For certainly the Apostle speaks here of the custom of swearing as of a holy practice, and approved by God. Moreover, he does not say of it as having been formerly in use, but as of a thing still practiced. Let it then be employed as a help to find out the truth when other proofs are wanting.
John Calvin, Commentary on Hebrews 6.5
One part of the religious regard the Jews were taught to pay to their God was to swear by his name, Deut. x. 20 . But they affronted him, instead of doing him honour, if they called him to be witness to a lie.
Matthew Henry, Commentary on Exodus 20.1
We must give honour to God, in swearing by his name ( v. 20 ); so give him the honour of his omniscience, his sovereignty, his justice, as well as of his necessary existence. Swear by his name, and not by the name of any creature, or false god, whenever an oath for confirmation is called for.
Matthew Henry, Commentary on Deuteronomy 10.2
10 passages · 8 writers · 1200s to 1800s
Writers name the occasions, authority, and conditions under which a Christian may swear.
Reply to Objection 3: Even as a medicine is useful for healing, and yet, the stronger it is, the greater harm it does if it be taken unduly, so too an oath is useful indeed as a means of confirmation, yet the greater the reverence it demands the more dangerous it is, unless it be employed aright; for, as it is written ( Ecclus. 23:13 ), "if he make it void," i.e. if he deceive his brother, "his sin shall be upon him: and if he dissemble it," by swearing falsely, and with dissimulation, "he offendeth double," [because, to wit, "pretended equity is a twofold iniquity," as Augustine [*Enarr. in Ps. lxiii, 7] declares]: "and if he swear in vain," i.e. without due cause and necessity, "he shall not be justified."
Thomas Aquinas, Summa Theologica II-II.Q89.A5
Reply to Objection 2: According to Augustine (De Serm. Dom. in Monte i. 17): "If you have to swear, note that the necessity arises from the infirmity of those whom you convince, which infirmity is indeed an evil. Accordingly He did not say: 'That which is over and above is evil,' but 'is of evil.' For you do no evil; since you make good use of swearing, by persuading another to a useful purpose: yet it 'comes of the evil' of the person by whose infirmity you are forced to swear." Reply to Objection 3: He who swears tempts not God, because it is not without usefulness and necessity that he implores the Divine assistance.
Thomas Aquinas, Summa Theologica II-II.Q89.A2
Q. But may we swear an oath in God’s name if we do it reverently? A. Yes, when the government demands it, or when necessity requires it, in order to maintain and promote truth and trustworthiness for God’s glory and our neighbor’s good. Such oath-taking is grounded in God’s Word 1 and was rightly used by the saints in the Old and New Testaments.
Reformed Churches, Heidelberg Catechism 101
As we confess that vain and rash Swearing is forbidden Christian men by our Lord Jesus Christ, and James his Apostle, so we judge, that Christian Religion doth not prohibit, but that a man may swear when the Magistrate requireth, in a cause of faith and charity, so it be done according to the Prophet’s teaching, in justice, judgement, and truth.
Church of England, Thirty-Nine Articles 39
The name of God only is that by which men ought to swear, and therein it is to be used with all holy fear and reverence. Therefore, to swear vainly, or rashly, by that glorious and dreadful Name; or, to swear at all by any other thing, is sinful, and to be abhorred. Yet, as in matters of weight and moment, an oath is warranted by the Word of God, under the new testament as well as under the old; so a lawful oath, being imposed by lawful authority, in such matters, ought to be taken.
Westminster Assembly, Westminster Confession of Faith 22.2
We must swear that only which is true, in truth and in righteousness, not daring to assert that which is false, or which we do not know to be true, nor to assert that as certain which is doubtful, nor to promise that which we mean not to perform, nor to violate the promise we have made. To say that which is untrue, or to do that which is unrighteous, is bad, but to back either with an oath is much worse. (3.) We must do it solemnly, swear in judgment, that is, when judicially called to it, and not in common conversation. Rash swearing is as great a profanation of God's name as solemn swearing is an honour to it.
Matthew Henry, Commentary on Jeremiah 4.1
Not that all swearing is sinful; so far from that, if rightly done, it is a part of religious worship, and we in it give unto God the glory due to his name. … That we must not swear at all, but when we are duly called to it, and justice or charity to our brother, or respect to the commonwealth, make it necessary for the end of strife ( Heb. vi. 16 ), of which necessity the civil magistrate is ordinarily to be the judge.
Matthew Henry, Commentary on Matthew 5.7
Herod made a foolish promise, and confirmed it by a wicked oath, Mat 14:9. Promises should not be made without knowing what is promised, and without knowing that it will be right to perform them. Oaths are always wicked except when made before a magistrate, and on occasions of real magnitude.
Albert Barnes, Notes on the Bible Matthew 14:34
The Lord Jesus forbids all vain and light swearing altogether. All swearing by created things, even when God's name is not brought forward--all calling upon God to witness, excepting on the most solemn occasions, is a great sin.
J.C. Ryle, Expository Thoughts on Matthew Matthew 5:21-37
Augustine’s rule on this subject is good: “Quantum ad me pertinet, juro, sed quantum mihi videtur, magna necessitate compulsus.”Sermon CLXXX. 10 [ix.]; Works, edit. Benedictines, Paris, 1837, vol. v. p. 1250, a. The multiplicity of oaths is a great evil. The rapid irreverent administration of them is profane.
Charles Hodge, Systematic Theology III.19.7
15 passages · 7 writers · 300s to 1700s
Writers address whether an oath may be sworn by anything other than God.
Wherefore it is the duty of a man of God, as he is a Christian, not to swear by the sun, or by the moon, or by the stars; nor by the heaven, nor by the earth, by any of the elements, whether small or great. For if our Master charged us not to swear by the true God, that our word might be firmer than an oath, nor by heaven itself, for that is a piece of heathen wickedness, nor by Jerusalem, nor by the sanctuary of God, nor the altar, nor the gift, nor the gilding of the altar, nor one’s own head, for this custom is a piece of Judaic corruption, and on that account was forbidden; and if He exhorts the faithful that their yea be yea, and their nay, nay, and says that “what is more than these is of the evil one,” how much more blameable are those who appeal to deities falsely so called as the objects of an oath, and who glorify imaginary beings instead of those that are real, whom God for their perverseness “delivered over to foolishness, to do those things that are not convenient!”
Anonymous (ANF), Constitutions of the Holy Apostles 6.2
But it may be asked why, when it was said, “But I say unto you, Swear not at all,” it was added, “neither by heaven, for it is God’s throne,” etc., up to “neither by thy head.” I suppose it was for this reason, that the Jews did not think they were bound by the oath, if they had sworn by such things: and since they had heard it said, “Thou shalt perform unto the Lord thine oath,” they did not think an oath brought them under obligation to the Lord, if they swore by heaven, or earth, or by Jerusalem, or by their head; and this happened not from the fault of Him who gave the command, but because they did not rightly understand it. Hence the Lord teaches that there is nothing so worthless among the creatures of God, as that any one should think that he may swear falsely by it; since created things, from the highest down to the lowest, beginning with the throne of God and going down to a white or black hair, are ruled by divine providence. “Neither by heaven,” says He, “for it is God’s throne; nor by the earth, for it is His footstool:” i.e. , when you swear by heaven or the earth, do not imagine that your oath does not bring you under obligation to the Lord; for you are convicted of swearing by Him who has heaven for His throne, and the earth for His footstool.
Augustine of Hippo, Our Lord’s Sermon on the Mount 2.17
I answer that, As stated above (A[1], ad 3), there are two kinds of oath. One is uttered a simple contestation or calling God as witness: and this kind of oath, like faith, is based on God's truth. Now faith is essentially and chiefly about God Who is the very truth, and secondarily about creatures in which God's truth is reflected, as stated above ( Q[1], A[1] ). In like manner an oath is chiefly referred to God Whose testimony is invoked; and secondarily an appeal by oath is made to certain creatures considered, not in themselves, but as reflecting the Divine truth. Thus we swear by the Gospel, i.e. by God Whose truth is made known in the Gospel; and by the saints who believed this truth and kept it.
Thomas Aquinas, Summa Theologica II-II.Q89.A6
As to Joseph's oath by the health of Pharaoh this may be understood in both ways: either by way of a curse, as though he pledged Pharao's health to God; or by way of contestation, as though he appealed to the truth of God's justice which the princes of the earth are appointed to execute. Reply to Objection 1: Our Lord forbade us to swear by creatures so as to give them the reverence due to God.
Thomas Aquinas, Summa Theologica II-II.Q89.A6
There is therefore under the Papacy a base and an intolerable idolatry, for the Papists swear by dead saints. … In short, we must bear in mind, that when necessity constrains us to swear, God is ever the sole judge, and that therefore his name is profaned when we swear by another.
John Calvin, Commentary on Jeremiah and Lamentations, Vol. 5 1.2.14
For it is a clear precept of God’s law, ‘By the name of thy God shalt thou swear.’ … We may hence doubtlessly conclude, that God is deprived of his right, whenever we swear by the sun, or by the moon, or by the dead, or by any creatures.
John Calvin, Commentary on Habakkuk, Zephaniah, and Haggai Zephaniah 1.5
Neither by heaven It is a mistake to explain these words as meaning, that such forms of swearing are condemned by Christ as faulty, on the ground that we ought to swear by God only. The reasons which he brings forward tend rather to the opposite view, that we swear by the name of God even when we name the heaven, and the earth: because there is no part of the world on which God has not engraved the marks of his glory. But this statement appears not to agree with the precept of the law, in which God expressly commands us to “swear by his name,” ( Deuteronomy 6:13 ;) and likewise with so many passages of Scripture, in which he complains, that injury is done to him, if we swear by creatures. I reply: It is a corruption allied to idolatry, when we appeal to them either as having a right to judge, or authority to prove testimony: for we must look at the object of swearing. It is an appeal which men make to God to revenge falsehood, and to uphold truth. This honor cannot be transferred to another, without committing an outrage on the divine majesty.
John Calvin, Harmony of the Evangelists, Vol. 1 5.48
There are indeed various kinds of protestations; but the chief one is, when we refer to God as a judge and directly appeal to his judgmentseat; another is, when we name things especially dear to us as our life, or our head, or anything of this kind; and the third is, when we call creatures as witnesses before God. But in all these ways we swear properly by no other than by God. hence they betray their impiety no less than their ignorance, who contend that it is lawful to connect dead saints with God so as to attribute to them the right of punishing.
John Calvin, Commentary on Hebrews 6.5
And in our own times, those who swear by angels, or by departed saints, take from God what belongs to him, and ascribe to them a divine majesty. The case is different, when men swear by heaven and earth, with a view to the Creator himself: for, in that case, the sanctity of the oath is not founded on creatures, but God alone is appealed to as a witness, by bringing forward the symbols of his glory.
John Calvin, Harmony of the Evangelists, Vol. 1 5.48
But when any one swears by heaven or the temple, and does not think that there is any divinity in the heavens or in the temple, it is the same as though he swore by God himself, as it appears from Matthew 23:20-22 ; and Christ, when he forbade us to swear by heaven or by the earth, did not condemn such modes of swearing as inconsistent with his word, but as only useless and vain. At the same time he showed that God’s name is profaned by such expressions: ‘They who swear by heaven, swear also by him who inhabits heaven; they who swear by the temple, swear also by him who is worshipped in the temple, and to whom sacrifices are offered.’
John Calvin, Commentary on Habakkuk, Zephaniah, and Haggai Zephaniah 1.5
It is to be noted that, though in an idle oath one sins more when he swears by the Creator than by the creature, it is more difficult to swear in the right way with truth, necessity and reverence by the creature than by the Creator, for the following reasons. First Reason. The first: When we want to swear by some creature, wanting to name the creature does not make us so attentive or circumspect as to telling the truth, or as to affirming it with necessity, as would wanting to name the Lord and Creator of all things.
Ignatius of Loyola, The Spiritual Exercises 1.3
It is not without cause the Lord has, by a special commandment, required us to swear by his name, and, by a special prohibition, forbidden us to swear by other gods.
John Calvin, Institutes of the Christian Religion II.8
But when nothing else is intended than to confirm what is said by an appeal to the holy name of God, although it is done indirectly, yet his majesty is insulted by all frivolous oaths.
John Calvin, Institutes of the Christian Religion II.8
Q. May we also swear by saints or other created things? A. No. A legitimate oath is calling upon God as the one who knows my heart to witness to the truth and to punish me if I swear falsely. 1 No created thing is worthy of such honor.
Reformed Churches, Heidelberg Catechism 102
That we must not swear by any other creature. It should seem there were some, who, in civility (as they thought) to the name of God, would not make use of that in swearing, but would swear by heaven or earth, &c. This Christ forbids here ( v. 34 ) and shows that there is nothing we can swear by, but it is some way or other related to God, who is the Fountain of all beings, and therefore that it is as dangerous to swear by them, as it is to swear by God himself: it is the verity of the creature that is laid at stake; now that cannot be an instrument of testimony, but as it has regard to God, who is the summum verum—the chief Truth.
Matthew Henry, Commentary on Matthew 5.7
12 passages · 4 writers · 300s to 1700s
Writers argue that habitual swearing leads to perjury and urge Christians to abstain from oaths or reduce them.
It is especially desirable that attention should be given to the case of persons in power who threaten on oath to do some hurt to those under their authority. The remedy is twofold. In the first place, let them be taught not to take oaths at random: secondly, not to persist in their wicked determinations. Any one who is arrested in the design of fulfilling an oath to injure another ought to shew repentance for the rashness of his oath, and must not confirm his wickedness under the pretext of piety. Herod was none the better for fulfilling his oath, when, of course only to save himself from perjury, he became the prophet’s murderer. Swearing is absolutely forbidden, and it is only reasonable that the oath which tends to evil should be condemned.
Basil of Caesarea, The Letters 199
For man, who, through a habit of swearing, may slip into perjury, is rightly forbidden to swear: for he will be farther from perjury in proportion as he is far from swearing. For the man who sweareth, may swear truly or falsely: but he who sweareth not, cannot swear falsely; for he sweareth not at all.
Augustine of Hippo, Expositions on the Book of Psalms 110
Man is justly forbidden to swear: lest by the habit of swearing, since a man may be deceived, he fall into perjury. God alone swears securely, because He alone is infallible.
Augustine of Hippo, Expositions on the Book of Psalms 89
For, in the first place, he who is continually swearing, whether willingly or unwillingly; knowingly or unknowingly; in jest or in earnest; being frequently carried away by anger and by many other things, will most surely become perjured. And no one can gainsay this; so evident and generally allowed is the fact, that the man who swears frequently, must also be a perjurer.
John Chrysostom, The Homilies on the Statues to the People of Antioch 16
Hath God commanded, and darest thou to ask if it be possible for His law to be kept? Why, truly it is a thing impossible that His law should not be kept; and I am desirous to persuade you from present circumstances of this; that so far from its being impossible not to swear, it is impossible to swear. … God hath commanded thee to avoid oaths! and how sayest thou, it is impossible to avoid them!
John Chrysostom, The Homilies on the Statues to the People of Antioch 10
Dangerous, indeed, it is for any one to swear in a matter pertaining to himself; for we are forcibly impelled to do many things by the urgency of circumstances. But much more dangerous is it by the obligation of one’s own oath, to bind the determination of others; and especially where any one swears, not concerning one, or two, or three, but an unlimited multitude, which Saul then inconsiderately did, without thinking that it was probable that, in so vast a number, one at least might transgress the oath; or that soldiers, and soldiers too on campaign, are very far removed from moral wisdom, and know nothing of ruling the belly; more especially when their fatigue is great.
John Chrysostom, The Homilies on the Statues to the People of Antioch 16
Let all men understand that thou wilt choose to suffer anything rather than transgress the law of God; and they will abstain from compelling thee. For as a proof that it is not an oath which rendereth a man worthy of credit, but the testimony of his life, the uprightness of his conversation, and his good reputation, many have often split their throats with swearing, and yet have been able to convince no one; whereas others by a mere expression of assent, have been esteemed more deserving of belief than they who swore never so much.
John Chrysostom, The Homilies on the Statues to the People of Antioch 9
So when thou art about to put any one on his oath, restrain thyself; and stop; and say to him who is about to swear, “What shall I do with thee? God hath forbidden me to put any one on oath. … For when he seeth that we are thus afraid to put others on oath, much more will he himself be afraid to swear rashly.
John Chrysostom, The Homilies on the Statues to the People of Antioch 17
For assuredly, where a law is transgressed, it is improper to make mention of necessity; forasmuch as there is but one necessity which cannot be dispensed with, viz. that of not offending God! This, however, I say further; cut off in the meantime superfluous oaths, those that are taken uselessly, and without any necessity; those to your own family, those to your friends, those to your servants; and should you take away these, you will have no further need of me for the others.
John Chrysostom, The Homilies on the Statues to the People of Antioch 7
Further, do not make me this reply; “We have banished oaths for the most part, and we are rarely caught in that snare;” but let even this rarity of offending be got rid of. … If you perceive that you have been cheated out of one oath, weep, lament, as though your whole substance were lost.
John Chrysostom, The Homilies on the Statues to the People of Antioch 22
A man having once learnt to steal, and to wrong his neighbor, will presume full oft to trample upon his oath; if on the contrary he shrinks from swearing, he will much more shrink from injustice.
John Chrysostom, A Commentary on the Acts of the Apostles 9
It is being suspected of falsehood that leads men to swearing. Let it be known that your keep to truth, and are firm to your word, and by this means you will find there is no need to swear to what you say.
Matthew Henry, Commentary on James 5.2
5 passages · 3 writers · 300s to 1700s
Writers discuss whether and when a sworn oath must be kept.
For if inevitable death were threatened in order to compel a servant of God to swear that he would do something forbidden by laws both human and divine, it would be his duty to prefer death to such an oath, lest he should be guilty of a crime in fulfilling his oath. But in this case, in which the determined clamour of the people, and only this, was forcing the man, not to a crime, but to that which if it were done would be lawfully done; when, moreover, there was indeed apprehension lest some reckless men, such as are mixed with a multitude even of good men, should through love of rioting break out into some wicked deeds of violence, if they found a pretext for disturbance and for plausibly justifiable indignation, but there was no certainty of this fear being realized,—who will affirm that it is lawful to commit a deliberate act of perjury in order to escape from uncertain consequences, involving, I shall not say loss or bodily injury, but even death itself?
Augustine of Hippo, Letters of St. Augustin 1.112
For persons possessing any faith—and how much more the Christian faith!—to be unfaithful to their oath, I do not say by doing something contrary to it, but by hesitating at all as to its fulfilment, is utterly wrong. … Do you think that even if death, which in this case was feared without reason, were certainly imminent, a Christian might use the name of his Lord to confirm a lie, and call his God to be witness to a falsehood? For assuredly a Christian, if urged by the menace of instant death to perjure himself by false testimony, ought to fear the loss of honour more than the loss of life.
Augustine of Hippo, Letters of St. Augustin 1.113
In regard to the general position, the obligation of an oath ought to be held in the greatest sacredness, so that we may not, under the pretext of error, resile from pactions, even from those in which we have been deceived, since the sacred name of God is more precious than the wealth of a whole world.
John Calvin, Commentary on Joshua 9.2
Let us then remember, that whenever we perform not what we have pledged, not only wrong is done to men, but also to God himself, and that it is a sacrilege, and what is much more atrocious than theft, or fraud, or cruelty. Let us, therefore, learn from this passage to act in good faith, especially when the name of God is invoked, when he is appealed to as a witness and judge.
John Calvin, Commentary on Jeremiah and Lamentations, Vol. 4 34.10
If a man swears by heaven, he sins ( ch. v. 34 ); yet he shall not therefore be discharged from the obligation of his oath; no, God will make him know that the heaven he swears by, is his throne ( Isa. lxvi. 1 ); and he that swears by the throne, appeals to him that sits upon it; who, as he resents the affront done to him in the form of the oath, so he will certainly revenge the greater affront done to him by the violation of it. Christ will not countenance the evasion of a solemn oath, though ever so plausible.
Matthew Henry, Commentary on Matthew 23.2
5 passages · 4 writers · 100s to 1800s
Writers treat a sworn promise as binding and comment on keeping it.
But if the soldiers enrolled by you, and who have taken the military oath, prefer their allegiance to their own life, and parents, and country, and all kindred, though you can offer them nothing incorruptible, it were verily ridiculous if we, who earnestly long for incorruption, should not endure all things, in order to obtain what we desire from Him who is able to grant it.
Justin Martyr, The First Apology 39
I conclude, therefore, that if a private interest only is to be affected, everything which we may have promised by oath must be performed. And it is apparent from the words, that the Israelites were afraid lest they should expose the name of their God to disgrace among the nations of Canaan. For I think there is an emphasis in the expression — because they had sworn by the God of Israel. But a special reason left the Israelites at liberty to recede from the deceitful compact; for they had not only given up their own right, but improperly departed from the command of God, with which it was not lawful to interfere in the smallest iota. It was not in their power either to spare the vanquished or enact laws of surrender, whereas they now transact as if the business had been committed to them. We see, accordingly, that they twice profaned the name of God, while, under pretence of the oath, they persevered in defending what they had foolishly promised.
John Calvin, Commentary on Joshua 9.2
An oath of the Lord is a sacred thing, and not to be dallied with.
Matthew Henry, Commentary on Leviticus 5.1
He that ratifies a promise with an oath imprecates the divine vengeance if he wilfully break his promise, and has reason to expect that divine justice will take him at his word. God is not mocked, and therefore oaths are not to be jested with. The princes would keep their word, [1.] Though they lost by it. A citizen of Zion swears to his own hurt and changes not, Ps. xv. 4 .
Matthew Henry, Commentary on Joshua 9.3
But such is the solemnity of an oath, and such the importance of its inviolable sanctity being preserved, that it is better to suffer injustice than that an oath should be broken. The case where an oath is obtained by deceit is more difficult, for when such deceit is practised the juror did not intend to assume the obligation which the oath imposes. He might, therefore, plausibly argue that if he did not intend to assume an obligation, it was not assumed. But, on the other hand, the principle involved in the commercial maxim, caveat emptor, applies to oaths. A man is bound to guard against deception; and if deceived he must take the consequences.
Charles Hodge, Systematic Theology III.19.7
3 passages · 2 writers · 1500s
Writers comment on oaths in Scripture as lawful or sacred.
Was it necessary for Paul to go under oath? Yes. Paul is reporting personal history. How else would the churches believe him? The false apostles might say, “Who knows whether Paul is telling the truth?” Paul, the elect vessel of God, was held in so little esteem by his own Galatians to whom he had preached Christ that it was necessary for him to swear an oath that he spoke the truth.
Martin Luther, Commentary on Galatians 1:20
The expression, “an oath of the Lord shall be between them both,” is a remarkable one, whereby the obligation and sanctity of an oath are enforced, whilst Moses reminds us that God is the author of this sacred mode of attestation, and presides over it as its judge and avenger.
John Calvin, Harmony of the Law, Vol. 3 1.4.3
By mentioning, Live does Jehovah, he refers to the words which the godly also use when they make an oath; for when they appeal to the living God, it is the same thing as though they stood before his tribunal; and at the same time said, that they knew that though God may defer his vengeance, yet an account must be given, because he ever lives. Thus the godly acknowledge that there is nothing gained by delay, in case God suspends his vengeance, if they swear falsely. But the Prophet, as I have already said, applies this to hypocrites, who seemed to ascribe great honor to God, for nothing is more specious than their words: gall indeed was in their heart, while honey was on their lips. Hence the Prophet derides this false pretense, and says, “Even when they swear most solemnly as to the words used, and shew a high concern for religion, nevertheless they swear falsely.”
John Calvin, Commentary on Jeremiah and Lamentations, Vol. 1 5.2
3 passages · 3 writers · 300s to 1700s
Writers praise Christians who shun oaths or condemn rash and casual swearing.
Oaths were shunned by Gregory, that pure soul, worthy of the fellowship of the Holy Ghost, content with yea and nay, in accordance with the commandment of the Lord Who said, “I say unto you swear not at all.” Gregory could not bear to call his brother a fool, for he stood in awe of the threat of the Lord. Passion, wrath, and bitterness never proceeded out of his mouth.
Basil of Caesarea, The Letters 207
He who made a law for swearing rightly, and forbade perjury, has now charged us not to swear at all.
Anonymous (ANF), Constitutions of the Holy Apostles 7.4
Note, We have reason to suspect the truth of that which is backed with rash oaths and imprecations. None but the devil's sayings need the devil's proofs.
Matthew Henry, Commentary on Matthew 26.10
1 passage · 1 writer · 1500s
Calvin treats a promise made to God as a kind of swearing.
The rule of vowing also pertains to the keeping of the Third Commandment, since, by vowing, men exercise themselves in the sanctification of God’s name, and to promise anything to God is a kind of swearing. For what between men is called a covenant or agreement, with respect to God is a vow; and therefore it may be fitly called a sacred engagement, which not only is made with God as its witness, but which is contracted with God Himself.
John Calvin, Harmony of the Law, Vol. 2 3.2.3
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