Leviticus 18:10

Catholic Public Domain Version

You shall not uncover the nakedness of your son's daughter, or your daughter's daughter; for it is your own nakedness.

See the chapter Copy

You shall not uncover the nakedness of your father's wife's daughter, whom she bore to your father, and who is your sister.

You shall not uncover the nakedness of your sister, whether from father or from mother, whether she was born at home or abroad.