Matthew 5:34

But I say unto you, Swear not at all; neither by heaven, for it is the throne of God; nor by the earth, for it is the footstool of his feet; nor by Jerusalem, for it is the city of the great King. Neither shalt thou swear by thy head, for thou canst not make one hair white or black. But let your speech be Yea, yea; Nay, nay: and whatsoever is more than these is of the evil one.

The obvious meaning is that a Christian's word is his bond. He does not need to reinforce his words with any oath or any appeal for heaven to witness, or by any other device to underscore the truth of his remarks. A Christian's speech is limited to "Yes" and "No" with regard to oath. The only possible exception, and there is no unanimity of opinion even on this, is that of a Christian's taking a judicial oath to assure proper and legal testimony in a court of law. Many courts allow the conscientious adherent to our Saviour's words in this place the privilege of "affirming under the penalties of perjury" instead of taking the customary oath. Those who insist that a Christian may take such oaths point out that Christ, in this place, was clearly not talking about judicial oaths and that Almighty God himself is represented as taking an oath in these words, "Wherein God, being minded to show more abundantly unto the heirs of the promise the immutability of his counsel, interposed with an oath" (Hebrews 6:17).

Speaking the truth in love is a badge of true discipleship. Falsehood, evil-speakings, slander, backbiting, gossip, and idle talk of all kinds - these are surely prohibited to the child of God. One cannot help observing that Christ's way is almost as novel, untried, and astonishing as it was to the generation that first heard these words!

Various references to heaven, earth, Jerusalem, and one's head, are only examples of oaths which people of that day commonly employed.