Leviticus 18:17

ערות אשה ובתה THE NAKEDNESS OF A WOMAN AND HER DAUGHTER [THOU SHALT NOT UNCOVER] — Scripture forbids this only if the union with the first of these (whether it be the woman or her daughter) came about through a legal marriage. That is why Scripture uses the term לא תקח, the expression employed for "taking to wife in a legal way". Similarly with reference to the punishment for such a union it states, (Leviticus 20:14) "And if a man take (יקח) a wife and her mother, [it is wickedness; they shall be burnt with fire]" — an expression for "taking" to wife in a legal way. But if one has raped a woman he is permitted to marry her daughter (Yevamot 97a). שארה הנה means, they are closely related to one another. זמה means, an evil plan, as the Targum renders it‎ עצת חטאין , "a sinful plan"; the term is used because it is your evil inclination which counsels you to sin.

עֶרְוַ֥ת אִשָּׁ֛ה וּבִתָּ֖הּ לֹ֣א תְגַלֵּ֑ה אֶֽת־בַּת־בְּנָ֞הּ וְאֶת־בַּת־בִּתָּ֗הּ לֹ֤א תִקַּח֙ לְגַלּ֣וֹת עֶרְוָתָ֔הּ שַׁאֲרָ֥ה הֵ֖נָּה זִמָּ֥ה הִֽוא׃

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 foulness.