Matthew 5:31-38 New Revised Standard Version (NRSV)
31 “It was also said, ‘Whoever divorces his wife, let him give her a certificate of divorce.’ 32 But I say to you that anyone who divorces his wife, except on the ground of unchastity, causes her to commit adultery; and whoever marries a divorced woman commits adultery.
33 “Again, you have heard that it was said to those of ancient times, ‘You shall not swear falsely, but carry out the vows you have made to the Lord.’ 34 But I say to you, Do not swear at all, either by heaven, for it is the throne of God, 35 or by the earth, for it is his footstool, or by Jerusalem, for it is the city of the great King. 36 And do not swear by your head, for you cannot make one hair white or black. 37 Let your word be ‘Yes, Yes’ or ‘No, No’; anything more than this comes from the evil one.[a]
38 “You have heard that it was said, ‘An eye for an eye and a tooth for a tooth.’