Leviticus 18:6

2 “Speak to the Israelites and tell them: I am the LORD your God.

3 You must not follow the practices of the land of Egypt, where you used to live, and you must not follow the practices of the land of Canaan, into which I am bringing you. You must not walk in their customs.

4 You are to practice My judgments and keep My statutes by walking in them. I am the LORD your God.

5 Keep My statutes and My judgments, for the man who does these things will live by them. I am the LORD.

6 None of you are to approach any close relative to have sexual relations. I am the LORD.

7 You must not expose the nakedness of your father by having sexual relations with your mother. She is your mother; you must not have sexual relations with her.

8 You must not have sexual relations with your father’s wife; it would dishonor your father.

9 You must not have sexual relations with your sister, either your father’s daughter or your mother’s daughter, whether she was born in the same home or elsewhere.

10 You must not have sexual relations with your son’s daughter or your daughter’s daughter, for that would shame your family.

Read all of Leviticus 18