Deuteronomy 24:4
her former husband who sent her away is not allowed to take her again to be his wife. She has been defiled. That is an abomination before Jehovah, and you shall not bring sin on the land Jehovah your God gives you as an inheritance.
Jeremiah 3:1
It is said: If a man divorces his wife and she leaves him and marries another man, her first husband should not go back to her again. The land would become completely polluted. You have behaved like a prostitute who has many lovers. Now you want to come back to me! Says Jehovah.
Leviticus 18:24-28
Do not become unclean in any of these ways. By these practices all the nations that I am forcing out of your way have become unclean.
Joshua 22:17-18
Do you remember our sin at Peor, when Jehovah punished his own people with an epidemic? We are still suffering because of that. Was that not enough sin?