
Augustine of Hippo
Catena Aurea · Matthäusevangelium 5
It hath been said, Whosoever shall put away his wife, let him give her a writing of divorcement: 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.
(Serm. in Mont. i. 16.) Not only does He permit to put away a wife who commits fornication, but whoso puts away a wife by whom he is driven to commit fornication, puts her away for the cause of fornication, both for his own sake and hers.