(34) Swear not at all.--Not a few interpreters, and even whole Christian communities, as e.g. the Society of Friends, see in these words, and in James 5:12, a formal prohibition of all oaths, either promissory or evidential, and look on the general practice of Christians, and the formal teaching of the Church of England in her Articles (Art. xxxix.), as simply an acquiescence in evil. The first impression made by the words is indeed so strongly in their favour that the scruples of such men ought to be dealt with (as English legislation has at last dealt with them) with great tenderness. Their conclusion is, however, it is believed, mistaken: (1) Because, were it true, then in this instance our Lord would be directly repealing part of the moral law given by Moses, instead of completing and expanding it, as in the case of the Sixth and Seventh Commandments. He would be destroying, not fulfilling. (2) Because our Lord himself answered, when He had before been silent, to a solemn formal adjuration (Matthew 26:63-64), and St. Paul repeatedly uses such forms of attestation (Romans 1:9; 1Corinthians 15:31; 2Corinthians 1:23; Galatians 1:20; Philippians 1:8). (3) Because the context shows that the sin which our Lord condemned was the light use of oaths in common speech, and with no real thought as to their meaning. Such oaths practically involved irreverence, and were therefore inconsistent with the fear of God. The real purpose of an oath is to intensify that fear by bringing the thought of God's presence home to men at the very time they take them, and they are therefore rightly used when they attain that end. Practically, it must be admitted that the needless multiplication of oaths, both evidential and promissory, on trivial occasions, has tended, and still tends, to weaken awe and impair men's reverence for truth, and we may rejoice when their number is diminished. In an ideal Christian society no oaths would be needed, for every word would be spoken as by those who knew that the Eternal Judge was hearing them.

(34-35) Neither by heaven; . . . nor by the earth; . . . neither by Jerusalem.--Other formulae of oaths meet us in Matthew 23:16-22; James 5:12. It is not easy at first to understand the thought that underlies such modes of speech. When men swear by God, or the name of Jehovah, there is an implied appeal to the Supreme Ruler. We invoke Him (as in the English form, "So help me God") to assist and bless us according to the measure of our truthfulness, or to punish us if we speak falsely. But to swear by a thing that has no power or life seems almost unintelligible, unless the thing invoked be regarded as endowed in idea with a mysterious holiness and a power to bless and curse. Once in use, it was natural that men under a system like that of Israel, or, we may add, of Christendom, should employ them as convenient symbols intensifying affirmation, and yet not involving the speaker in the guilt of perjury or in the profane utterance of the divine name. Our Lord deals with all such formulae in the same way. If they have any force at all, it is because they imply a reference to the Eternal. Heaven is His throne, and earth is His footstool (the words are a citation from Isaiah 66:1), and Jerusalem is the city of the great King. To use them lightly is, therefore, to profane the holy name which they imply. Men do not guard themselves either against irreverence or perjury by such expedients.

Verse 34. - Swear not at all (cf. James 5:12). Yet, as St. Augustine points out, St. Paul took oaths in his writings (2 Corinthians 1:23; 2 Corinthians 11:31); and our Lord himself did not refuse to answer when put upon his oath (Matthew 26:63, 64). He, that is to say, and St. Paul after him, accepted the fact that there are times when a solemn oath must be taken. How, then, can we explain this absolute prohibition here? In that our Lord is not here thinking at all of formal and solemn oaths, but of oaths as the outcome of impatience and exaggeration. The thoughtlessness of fervent asseveration is often betrayed into an oath. Such an oath, or even any asseveration that passes in spirit beyond "yea, yea," "nay, nay," has its origin ἐκ τοῦ πονηροῦ; cf. Chaucer, "Sweryng sodeynly without avysement is eek a gret synne" ('Parson's Tale,' § 'De Ira'). Martensen, however ('Ethics, Individual,' § 100), takes the prohibition of oaths as formally unconditional and total, in accordance with the highest ideal of what man will hereafter be and require, and he sees the limitation, which he allows is to be given to these words, in the present conditions of human society. We have an ideal duty towards God, but we have also a practical duty to those among whom we live, and the present state of human affairs permits and necessitates oaths. Hence it was that even Christ submitted to them. Neither by heaven, etc. Our Lord further defines what he means by an oath. It does not mean only an expression in which God's Name is mentioned, but any expression appealing to any object at all, whether this be supraterrestrial, terrestrial, national, or personal. Although God's Name is often omitted in such cases, from a feeling of reverence, its omission does not prevent the asseveration being an oath. Heaven; Revised Version, the heaven; for the thought is clearly not the immaterial transcendental heaven, the abode of bliss, but the physical heaven (cf. Matthew 6:26, Revised Version). Heaven... footstool. Adapted from Isaiah 66:1, where it forms part of the glorious declaration that no material temple can contain God, that "the Most High dwelleth not in temples made with hands" as St. Stephen paraphrases it (Acts 7:48). The great King is seated enthroned in the heaven, with his feet touching the earth.

5:33-37 There is no reason to consider that solemn oaths in a court of justice, or on other proper occasions, are wrong, provided they are taken with due reverence. But all oaths taken without necessity, or in common conversation, must be sinful, as well as all those expressions which are appeals to God, though persons think thereby to evade the guilt of swearing. The worse men are, the less they are bound by oaths; the better they are, the less there is need for them. Our Lord does not enjoin the precise terms wherein we are to affirm or deny, but such a constant regard to truth as would render oaths unnecessary.But I say unto you, swear not at all,.... Which must not be understood in the strictest sense, as though it was not lawful to take an oath upon any occasion, in an affair of moment, in a solemn serious manner, and in the name of God; which may be safely done: but of rash swearing, about trivial matters, and by the creatures; as appears by what follows,

neither by heaven; which is directly contrary to the Jewish canons (m), which say,

"they that swear "by heaven", and by earth, are free.''

Upon the words in Sol 2:7, "I adjure you", &c. it is asked (n),

"by what does she adjure them? R. Eliezer says, by the heavens, and by the earth; by the hosts, the host above, and the host below.''

So Philo the Jew says (o) that the most high and ancient cause need not to be immediately mentioned in swearing; but the "earth", the sun, the stars, "heaven", and the whole world. So R. Aben Ezra, and R. David Kimchi, explain Amos 4:2. "The Lord God hath sworn by his holiness"; that is, say they, "by heaven": which may be thought to justify them, in this form of swearing; though they did not look upon it as a binding oath, and therefore if broken they were not criminal (p).

"He that swears by heaven, and by the earth, and by the sun, and the like; though his intention is nothing less than to him that created them, this is no oath.''

The reason why it is forbidden by Christ to swear by heaven, is,

for it is God's throne; referring to Isaiah 66:1 where he sits, the glory of his majesty shines forth, and is itself glorious and excellent, and not to be mentioned in a vain way; and especially, for the reason Christ elsewhere gives, Matthew 23:22 that "he that shall swear by heaven, sweareth by the throne of God, and by him that sitteth thereon"; so that they doubly sinned, first, by openly swearing by that which is God's creature; and then, by tacitly bringing God into their rash and vain oaths.

(m) Misn. Shebuot, c. 4. sect. 13. (n) Shirhashirim Rabba, fol. 10. 4. (o) De Special. leg. p 770. (p) Maimon. Hilch. Shebuot, c. 12. sect. 3.