Pseudo-Chrysostom
Catena Aurea · Matthäusevangelium 19
And it came to pass, that when Jesus had finished these sayings, he departed from Galilee, and came into the coasts of Judæa beyond Jordan; And great multitudes followed him; and he healed them there. The Pharisees also came unto him, tempting him, and saying unto him, Is it lawful for a man to put away his wife for every cause? And he answered and said unto them, Have ye not read, that he which made them at the beginning made them male and female, And said, For this cause shall a man leave father and mother, and shall cleave to his wife: and they twain shall be one flesh? Wherefore they are no more twain, but one flesh. What therefore God hath joined together, let not man put asunder. They say unto him, Why did Moses then command to give a writing of divorcement, and to put her away? He said unto them, Moses because of the hardness of your hearts suffered you to put away your wives: but from the beginning it was not so.
Therefore said He well, Moses suffered, not commanded. For what we command, that we ever wish; but when we suffer, we yield against our will, because we have not the power to put full restraint upon the evil wills of men. He therefore suffered you to do evil that you might not do worse; thus in suffering this he was not enforcing the righteousness of God, but taking away its sinfulness from a sin; that while you did it according to His law, your sin should not appear sin.