Pseudo-Chrysostom — as excerpted in the Catena Aurea on Matthew 5:31-32

“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 the bill of divorcement, not because it was a good practice in itself, but was the prevention of a worse evil.”