Oaths

33. Again, ye have heard that it hath been said, Thou shalt not swear falsely, but shalt perform unto the Lord thine oaths. "That is, when you take an oath, speak the truth.

34-35. But I say unto, Swear not at all; neither by heaven, for it is God's throne; nor by the earth, for it is the footstool of His feet; neither by Jerusalem, for it is the city of the great king. Since, the Jews had heard God say, "Heaven is My throne, and earth is My footstool," they would swear by such things. In prohibiting them from swearing by these things, the Lord does not say, "Do not swear by them because heaven is good and great, and earth is useful." Instead He says, "Do not swear by them because the one is the throne of God and the other is His footstool," so that idolatry would not occur. For they might make gods out of those elements by which they swore, which indeed had happened before.

36. Neither shalt thou swear by thy head, because thou canst not make one hair white or black. God alone swears by Himself as He is not subject to anyone or anything. Since we do not have authority over ourselves, how can we swear by our own head? It is the property of another. But if you think your head is your own, then change one hair of it if you can.

37. But let your speech be, Yea, yea; Nay, nay. Lest you ask, "How then will people believe what I say?" He says, "They will believe you if you always tell the truth and never swear at all." For no one is disbelieved more than he who is eager to swear that he speaks the truth. What is more than this, is of the evil one. The Lord says that swearing, which is more than "Yea" and "Nay," is of the devil. But, you will ask, is the law of Moses, which bids us to swear, also, evil? Learn, then, that at that time it was not evil to, swear. But after Christ, it is evil. And so it is with circumcision and, in short, with all the Judaic practices. So also, to nurse at the breast is proper for infants, but shameful for adults.