Leviticus 18:3

18:3 You must not do as they do in the land of Egypt where you have been living, and you must not do as they do in the land of Canaan into which I am about to bring you; you must not walk in their statutes.

Leviticus 18:11

18:11 You must not have sexual intercourse with the daughter of your father’s wife born of your father; she is your sister. You must not have intercourse with her.