Leviticus 18:9

Thy sister, by both parents. The daughter of thy father, or daughter of thy mother; thy sister by either of thy parents. Whether she be born at home, to wit, of thy father by another wife, whom he hath taken into his house. Or born abroad; either of thy mother, by another, whether a former or a second husband, in another house and family; or of thy father by some strange woman, for there might be some doubt in these cases.