Leviticus 18:17

Thou shalt not uncover the nakedness of a woman and her daughter, neither shalt thou take her son’s daughter, or her daughter’s daughter, to uncover her nakedness; for they are her near kinswomen: it is wickedness.

Cross-reference

Leviticus 20:14 prescribes burning as punishment for the very act forbidden here — marrying a woman and her daughter.

Deuteronomy 27:23 curses lying with one's mother-in-law, a related family incest prohibition (wife's mother).

Amos 2:7 Related theme

Amos 2:7 condemns father and son having sex with the same girl — another family sexual sin, though not the same relationship.