And the phrase: Any case, of the latter clause, which is referring to betrothal with a transgression, serves to include a convert who married a mamzeret. But if you say that the mishna is in accordance with the opinion of Rabbi Yosei, then granted the phrase: Any case where there is betrothal and no transgression, of the first clause, is as we said, i.e., it includes an Israelite who married a ḥalala; and the phrase: In which case is this applicable, is as we said, i.e., to the exclusion of Ravin or Rav Dimi, and the case of a convert who married a mamzeret. But what does the phrase: Any case, of the latter clause, serve to add?

The Gemara responds: And according to your reasoning, the same question applies to Rabbi Yehuda as well: Why do I need the phrase: In which case is this applicable, of the latter clause? Rather, you must say: Since the mishna taught its first clause using the phrase: In which case is this applicable, it also taught its latter clause using the phrase: In which case is this applicable, merely for the sake of stylistic consistency. So too here, with regard to Rabbi Yosei’s opinion, one can say: Since the mishna taught the first clause with the expression: Any case, it also taught its latter clause with: Any case.

§ The Gemara discusses the aforementioned matter itself: When Ravin came from Eretz Yisrael, he said that Rabbi Yoḥanan says: With regard to the nations, if members of two different nations married when they were gentiles, follow the male to determine the status of their child. If they converted before marriage, follow the flawed lineage of the two.

The Gemara analyzes this statement: What is the meaning of: With regard to the nations, follow the male? As it is taught in a baraita: From where is it derived with regard to one member of the nations outside Eretz Yisrael who engaged in intercourse with a Canaanite woman and fathered a son from her, that you are permitted to purchase the son as a slave, and he is not considered a member of the Canaanite nations, who are not allowed to live in Eretz Yisrael?

The verse states: “And also of the children of the residents who sojourn with you, of them you may buy” (Leviticus 25:45), which indicates that there is a way in which one may purchase slaves from the inhabitants of Canaan. One might have thought that even with regard to a Canaanite slave who engaged in intercourse with a maidservant from the other nations and fathered a son, that you are permitted to buy the son as a slave. Therefore, the verse states: “Which they have begotten in your land” (Leviticus 25:45). This means that one may purchase from those who are merely begotten in your land, whose fathers are not from the Canaanite nations, but not from those who reside in your land, i.e., whose fathers are from the seven Canaanite nations.

The Gemara discusses the second clause of Rabbi Yoḥanan’s statement: If they converted, follow the flawed lineage of the two. To which case does this refer? If we say that it is referring to an Egyptian man who married an Ammonite woman, what flawed lineage is there here? The lineage of an Ammonite woman who converts is not flawed at all, as the Sages expounded that the verse: “An Ammonite…shall not enter into the assembly of the Lord” (Deuteronomy 23:4) is referring to an Ammonite man but not an Ammonite woman, which means that she can marry a Jew of unflawed lineage.

Rather, it must be referring to an Ammonite man who married an Egyptian woman, and in that case if the child is a male, cast him after his father, and render him permanently prohibited from entering the congregation as an Ammonite male. And if the child born to them is a female, cast her after the mother, so that she is considered a second-generation Egyptian, who may not marry a Jew of unflawed lineage.

§ The mishna teaches that in any case where a woman cannot join in betrothal with him, but she can join in betrothal with others, the offspring is a mamzer. The Gemara explains: From where are these matters derived? As Rabbi Ḥiyya bar Abba says that Rabbi Yoḥanan says, and some determined that it was said in the name of Rabbi Yannai; and Rav Aḥa, son of Rava, determined that it was said in the name of Rabbi Yosei HaGelili: The verse states with regard to a divorced woman: “And she departs out of his house, and goes and becomes another man’s wife” (Deuteronomy 24:2). This teaches that she can become the wife of others, but not of relatives, i.e., betrothal to forbidden relatives does not take effect.

Rabbi Abba objects to this: But one can say and explain that the term “another” in the verse indicates: But not to her husband’s son, i.e., betrothal is ineffective only in the case of a prohibition that warrants court-imposed capital punishment, not one that warrants karet. The Gemara rejects this suggestion: With regard to a son it is explicitly written: “A man shall not take his father’s wife” (Deuteronomy 23:1), which means that betrothal is ineffective in this situation. If so, why do I need the emphasis of the term “another”? Learn from this term that she may marry others but not relatives.

The Gemara challenges this explanation: But one can say that both this verse and that verse are referring to a son and yet both are necessary, as this verse: “Shall not take,” is referring to the halakha ab initio. It does not mean that betrothal is ineffective, but merely that one may not marry his father’s wife. And that verse: “And becomes another man’s wife,” teaches that even after the fact, if the son attempted to betroth his father’s wife, his act is of no consequence.

The Gemara responds: One learns that betrothal is ineffective in this case ab initio from a different source, as it is derived from the prohibition proscribing a wife’s sister by the following a fortiori inference: If, with regard to the prohibition proscribing a wife’s sister, whose transgression is punished with karet, she cannot be betrothed by her sister’s husband, in accordance with the verse: “And you shall not take a woman with her sister” (Leviticus 18:18), then with regard to cases that entail liability to receive court-imposed capital punishment, e.g., intercourse with one’s father’s wife, is it not all the more so the case that betrothal does not take effect?

The Gemara suggests another interpretation of the verses. But as the verse has already prohibited betrothal to a wife’s sister, one can say as follows: Both this verse: “You shall not take” (Leviticus 18:18), and that one: “Becomes another man’s wife” (Deuteronomy 24:2), are referring to a wife’s sister, as this one: “You shall not take,” prohibits this relationship ab initio, whereas that verse: “Another man’s wife,” teaches that this betrothal is of no effect even after the fact. The Gemara responds: Yes, it is indeed so. The verse should be interpreted in this manner.

The Gemara asks: We found a source for the prohibition proscribing a wife’s sister; from where do we derive that betrothal is also ineffective for the other forbidden relations? The Gemara answers: We derive it from the case of a wife’s sister, by means of the following analogy: Just as the prohibition with regard to a wife’s sister, which is specified by the Torah, is a prohibition of a forbidden relative that is punished with karet for its intentional transgression and requires a sin-offering for its unwitting transgression, and betrothal is ineffective in this case, so too, with regard to any prohibition that involves a forbidden relative whose intentional transgression is punished with karet and whose unwitting transgression renders one liable to bring a sin-offering, betrothal is likewise ineffective in those cases.

The Gemara asks: Granted, virtually all other forbidden relatives can be derived in this manner. But the cases of a married woman and a brother’s wife are exceptions, and the analogy in these cases can be refuted as follows. What is unique about a wife’s sister is that she is not permitted in the case of a mitzva, as even where the mitzva of levirate marriage would apply, one still may not marry one’s wife’s sister. Will you say the same with regard to a brother’s wife, who is permitted in the case of the mitzva of levirate marriage?

With regard to a married woman the interpretation can likewise be refuted: What is unique about these cases of a wife’s sister and a brother’s wife is that they cannot be permitted during the lives of those whose existence renders them prohibited, as neither a wife’s sister nor a brother’s wife can be permitted while the person who causes the prohibition is alive. This caveat is added because one’s wife’s sister does become permitted once his wife has died. Will you say the same with regard to a married woman, who can become permitted during the life of the one who renders her forbidden, by means of a divorce?

Rather, this halakha, that betrothal is ineffective for other forbidden relatives, is derived from a different source, as Rabbi Yona says, and some say this was taught by Rav Huna, son of Rav Yehoshua: The verse states explicitly in the chapter dealing with forbidden relatives: “Whoever shall do any of these abominations shall be cut off” (Leviticus 18:29). In this verse all those with whom relations are forbidden are juxtaposed to one another, and therefore also to a wife’s sister: Just as betrothal is not effective in the case of a wife’s sister, so too, betrothal is not effective with regard to all those with whom relations are forbidden.

The Gemara asks: If so, that this halakha is derived from here,