Imamat 18:12

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

Imamat 18:15

18:15 You must not have sexual intercourse with your daughter-in-law; she is your son’s wife. You must not have intercourse with her.

[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.