Leviticus 18:9

18:9 You must not have sexual intercourse with your sister, whether she is your father’s daughter or your mother’s daughter, ¹  whether she is born in the same household or born outside it; ²  you must not have sexual intercourse with either of them. ³ 

Leviticus 18:11

18:11 You must not have sexual intercourse with the daughter of your father’s wife born of your father; she is your sister. You must not have intercourse with her. ⁴ 

Leviticus 20:17

20:17 “‘If a man has sexual intercourse with ⁵  his sister, whether the daughter of his father or his mother, so that he sees her nakedness and she sees his nakedness, it is a disgrace. They must be cut off in the sight of the children of their people. ⁶  He has exposed his sister’s nakedness; he will bear his punishment for iniquity. ⁷ 

¹ tn Heb “the daughter of your father or the daughter of your mother.”

² tn Heb “born of house or born of outside.” CEV interprets as “whether you grew up together or not” (cf. also TEV, NLT).

³ tc Several medieval Hebrew mss, Smr, LXX, and Syriac have “her nakedness” rather than “their nakedness,” thus agreeing with singular “sister” at the beginning of the verse.

⁴ tn Heb “The nakedness of the daughter of your father’s wife born of your father, she is your sister; you must not uncover her nakedness.” That is, a half sister, the daughter of the man’s father by another wife, who is not the man’s mother, is to be considered a true sister. Therefore, the man must not have sexual intercourse with her.

⁵ tn Heb “takes.” The verb “to take” in this context means “to engage in sexual intercourse,” though some English versions translate it as “marry” (e.g., NIV, NCV, TEV, CEV).

⁶ tn Regarding the “cut off” penalty, see the note on Lev 7:20.

⁷ tn See the note on Lev 17:16 above.