Ibn Ezra on Leviticus 18:16/אבן עזרא על ויקרא י״ח:ט״ז

1THOU SHALT NOT UNCOVER THE NAKEDNESS OF THY BROTHER’S WIFE. This is explained in the Torah portion If brethren dwell together (Deut. 25:5).

2To the one who asks why didn’t Scripture mention a daughter, [I reply] that the daughter is stated in Thou shalt not uncover the nakedness of a woman and her daughter (Lev. 18:17), whether or not it is his daughter, for once he has slept with the mother the daughter is prohibited.