Chagigah 11B

לבתו מאנוסתו, דלא כתיבא.

with regard to his daughter born from the woman he raped, which is not written explicitly in the Torah. It is forbidden for this man to have sex with this daughter, despite the fact that she is not the daughter of his wife, as he did not marry her mother.

דאמר רבא, אמר לי רבי יצחק בר אבדימי: אתיא ״הנה״ ״הנה״.

As Rava said: R' Yitzḥak bar Avdimi said to me that this halakha is derived by means of a verbal analogy between the term they [hena], an unusual form of this word, written in one context, and the same term, they, written elsewhere. As it is written: “The nakedness of a woman and her daughter…you should not take…they [hena] are near kinswomen; it is lewdness” (Leviticus 18:17). And it is written: “The nakedness of your son’s daughter, or of your daughter’s daughter, even their nakedness you should not uncover; for they [hena] are your own nakedness” (Leviticus 18:10). This indicates that every daughter, even from the rape of a woman who is not one’s wife, is forbidden, just like one’s daughter from his wife.

אתיא ״זימה״ ״זימה״.

Furthermore, the punishment for this transgression is derived from a verbal analogy between: “It is lewdness [zima]” (Leviticus 18:17), which is written with regard to a woman and her daughter, and the same term “lewdness” that appears elsewhere, as it is stated: “And if a man take with his wife also her mother, it is lewdness [zima]: They should be burnt with fire, both he and they” (Leviticus 20:14).

הן הן גופי תורה. הני ⁠— אין, הנך לא? אלא אימא: הן והן גופי תורה.

§ The Mishnah taught: These [hen hen] are the essential parts of the Torah. The Talmud asks: These, the topics mentioned in the Mishnah, which are not written explicitly but for which there is ample basis in the Torah, yes, they are the essential parts of Torah, whereas those other categories listed in the Mishnah that are written explicitly, no, they are not essential? Rather, one must say that both these and those [hen vehen] are the essential parts of the Torah. Every part of the Torah is essential, whether or not it is written explicitly.