Leviticus 18:7-9

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 your father’s nakedness. ⁹ You shall not uncover the nakedness of your sister, the daughter of your father or the daughter of your mother, whether born at home or born abroad.