Leviticus 18:15

‘If there is a man who lies with his daughter-in-law, both of them shall surely be put to death; they have committed perversion. Their bloodguiltiness is upon them.

“One has also done what is an abomination with his neighbor’s wife, and another has lewdly defiled his daughter-in-law. And another in you has violated his sister, his father’s daughter.

but that we write to them that they abstain from things contaminated by idols and from sexual immorality and from what is strangled and from blood.