Leviticus 19:19-20

19The people must obey God's rules. They must not let two different kinds of animals have sex together. They must not put two different kinds of seeds in one field. They must not make clothes from two different materials.

20A slave girl belongs to a man. Another man must not have sex with her. If he does, he is doing a wrong thing. But the girl is not free. He has not bought her. You must punish them. But you must not kill them because the girl was not free.