Leviticus 18:10

18:10 You must not expose the nakedness of your son’s daughter or your daughter’s daughter by having sexual intercourse with them, because they are your own nakedness.

Leviticus 18:17

18:17 You must not have sexual intercourse with both a woman and her daughter; you must not take as wife either her son’s daughter or her daughter’s daughter to have intercourse with them. They are closely related to her – it is lewdness.