Leviticus 18:9-11

9You are not to have sexual intercourse with your sister, either your father’s daughter or your mother’s, whether born at home or born elsewhere. You are not to have sex with her.

10You are not to have sexual intercourse with your son’s daughter or your daughter’s daughter, for they are your family.

11You are not to have sexual intercourse with your father’s wife’s daughter, who is adopted by your father; she is your sister.