Augustine of Hippo
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.
(Cont. Faust. xix. 29.) Behold now out of the books of Moses it is proved to the Jews that a wife may not be put away. For they thought that they were doing according to the purport of Moses’ law when they did put them away. This also we learn hence by the testimony of Christ Himself, that it was God who made it thus, and joined them male and female; which when the Manichæans deny, they are condemned, resisting the Gospel of Christ.