Matthew 5:36-39

36Neither shalt thou swear by thy head, because thou canst not make one hair white or black. 37But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil.

38Ye have heard that it hath been said, An eye for an eye, and a tooth for a tooth: 39But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also.