Imamat 18:12

18:12 You must not have sexual intercourse with your father’s sister; she is your father’s flesh. ¹ 

Imamat 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. ² 

[18:12]  ¹ tc A few medieval Hebrew mss, the LXX, Syriac, and Vulgate all read “because she is the flesh of your father,” like the MT of v. 13.

[18:11]  ² 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.