Why
Matthew 5:31
It hath been said, Whosoever shall put away his wife, let him give her a writing of divorcement:
Deuteronomy 24:1-4
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.
2
And when she is departed out of his house, she may go and be another man's wife.
3
And if the latter husband hate her, and write her a bill of divorcement, and giveth it in her hand, and sendeth her out of his house; or if the latter husband die, which took her to be his wife;
4
Her former husband, which sent her away, may not take her again to be his wife, after that she is defiled; for that is abomination before the LORD: and thou shalt not cause the land to sin, which the LORD thy God giveth thee for an inheritance.
Isaiah 50:1
Thus saith the LORD, Where is the bill of your mother's divorcement, whom I have put away? or which of my creditors is it to whom I have sold you? Behold, for your iniquities have ye sold yourselves, and for your transgressions is your mother put away.
Jeremiah 3:8
And I saw, when for all the causes whereby backsliding Israel committed adultery I had put her away, and given her a bill of divorce; yet her treacherous sister Judah feared not, but went and played the harlot also.
Mark 10:4
And they said, Moses suffered to write a bill of divorcement, and to put her away.
and to
Matthew 1:19
Then Joseph her husband, being a just man, and not willing to make her a publick example, was minded to put her away privily.
Malachi 2:16
For the LORD, the God of Israel, saith that he hateth putting away: for one covereth violence with his garment, saith the LORD of hosts: therefore take heed to your spirit, that ye deal not treacherously.