Leviticus 20:16-17

16“ ‘If a woman approaches an animal to have sexual relations with it, kill both the woman and the animal. They are to be put to death; their blood will be on their own heads. 17“ ‘If a man marries his sister, the daughter of either his father or his mother, and they have sexual relations, it is a disgrace. They are to be publicly removed from their people. He has dishonored his sister and will be held responsible.