Leviticus 18:11
You must not have sexual relations with the daughter of your father’s wife, born to your father; she is your sister.
Berean Standard Bible
The nakedness of thy father’s wife’s daughter, begotten of thy father, she is thy sister, thou shalt not uncover her nakedness.
“‘You shall not uncover the nakedness of your father’s wife’s daughter, conceived by your father, since she is your sister.