Matthew 5:27-32 (KJV)

²⁷ Ye have heard that it was said by them of old time, Thou shalt not commit adultery:

²⁸ But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart.

²⁹ And if thy right eye offend thee, pluck it out, and cast it from thee: for it is profitable for thee that one of thy members should perish, and not that thy whole body should be cast into hell.

³⁰ And if thy right hand offend thee, cut it off, and cast it from thee: for it is profitable for thee that one of thy members should perish, and not that thy whole body should be cast into hell.

³¹ It hath been said, Whosoever shall put away his wife, let him give her a writing of divorcement:

³² But I say unto you, That whosoever shall put away his wife, saving for the cause of fornication, causeth her to commit adultery: and whosoever shall marry her that is divorced committeth adultery.

Deuteronomy 24:1

When a man hath taken a wife, and married her, and it come to pass that she find no favour in his eyes, because he hath found some uncleanness in her: then let him write her a bill of divorcement, and give it in her hand, and send her out of his house.