“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.”
Matthew 5:32 — Greek Interlinear
Church Fathers on Matthew 5:32
The Lord had taught us above that our neighbour’s wife was not to be coveted, He now proceeds to teach that our own wife is not to be put away.
For touching Moses' allowance of divorce, the Lord and Saviour more fully explains in conclusion, that it was because of the hardness of the hearts of the husbands, not so much sanctioning discord, as checking bloodshed.
For when Moses brought the children of Israel out of Egypt, they were indeed Hebrews in race, but Egyptians in manners. And it was caused by the Gentile manners that the husband hated the wife; and if he was not permitted to put her away, he was ready either to kill her or ill-treat her. Moses therefore suffered a bill of divorcement, not because it was a good practice in itself, but was the prevention of a worse evil.