Yevamot 55B

אתיא ״ביאה״ ״ביאה״.

It is derived from a verbal analogy between the terms entering and entering. The verse states in the context of a prohibition: “A mamzer should not enter into the assembly of YHWH” (Deuteronomy 23:3), and in the context of a prohibition derived from a positive mitzva: “The children that are born to them of the third generation may enter into the assembly of YHWH” (Deuteronomy 23:9). Consequently, these types of prohibitions are equated.

יבמה לשוק, מנלן? אי למאן דאמר לאו ⁠— לאו, אי למאן דאמר עשה ⁠— עשה.

The Talmud poses another question: From where do we derive that the initial stage of sex is considered sex with regard to the prohibition against a yevama having sex with a man from the general public? The Talmud answers that there is no need for an independent source in this case: If you are asking according to the one who said that this is an ordinary prohibition, it is a prohibition like any other. If you are asking according to the one who said that this is a positive mitzva, it is a positive mitzva like any other.

אלא: יבמה ליבם מנלן? אתיא ״ביאה״ ״ביאה״.

Rather, the question is as follows: From where do we derive that a yevama is acquired by her yavam via the initial stage of sex? The Talmud answers: It is derived from a verbal analogy between the words entering and entering. This verb is used with regard to ordinary Torah prohibitions, as mentioned above, and also with regard to levirate marriage, in the verse “Her brother-in-law will have sex with her” (Deuteronomy 25:5).

אשה לבעלה מנלן? אתיא ״קיחה״ ״קיחה״.

The Talmud asks further: From where do we derive that a woman is betrothed to her husband through the initial stage of sex? The Talmud answers: It is derived from a verbal analogy between the words taking and taking. With regard to betrothal, the verse states: “When a man takes a wife and marries her” (Deuteronomy 24:1). This verb is also used with regard to forbidden sex, as in the verse: “And if a man should take his sister” (Leviticus 20:17).