And I say unto you, Whosoever shall put away his wife, except it be for fornication, and shall marry another, commits adultery: and whoever marries her who is put away does commit adultery.
All Commentaries on Matthew 19:9 Go To Matthew 19
Jerome
AD 420
It is fornication alone which destroys the relationship of the wife; for whenshe has divided one flesh into two, and has separated herself by fornication from her husband, she is not to be retained, lest she should bring her husband also under the curse, which Scripture has spoken, “He that keepeth an adulteress is a fool and wicked.”