Leviticus 18:7-9

New Revised Standard Version Catholic Edition

⁷ You shall not uncover the nakedness of your father, which is the nakedness of your mother; she is your mother, you shall not uncover her nakedness. ⁸ You shall not uncover the nakedness of your father’s wife; it is the nakedness of your father. ⁹ You shall not uncover the nakedness of your sister, your father’s daughter or your mother’s daughter, whether born at home or born abroad.