הנך תרתי דדמיין להדדי כחדא חשיב להו והא שיתסרי והא מכל מקום לדידי חזיין לן דכתיבן לאיסורא אמר ליה וליטעמיך אי הוה כתיב להיתירא מי הוות סמכת עלייהו דמר בריה דרבנא מי חתים עלייהו השתא נמי דכתיב לאיסורא לאו מר בריה דרבנא חתים עלייהו

Those two, the wife of a father’s father’s brother and the sister of a father’s father, are similar to each other and are counted as a single case, and so there are sixteen. The Gemara restates Rav Hillel’s challenge to Ameimar’s opinion: But in any case I myself saw them written as prohibited. Rav Ashi said to Rav Hillel: And according to your reasoning, if in the list it was written that they were permitted, would you have relied on that? Is the signature of Mar, son of Rabbana, signed on it? Although you saw the list, you don’t know for certain who wrote it. Now too, that it is written that they are prohibited, the same holds true; the signature of Mar, son of Rabbana, is not signed on it, and so it cannot be relied upon to reject the opinion of Ameimar.

תני דבי רבי חייא שלישי שבבנו ושבבתו ושבבן אשתו ושבבת אשתו שניה רביעי שבחמיו ושבחמותו שניה

§ One of the Sages of the school of Rabbi Ḥiyya taught: The third generation from one’s son and one’s daughter, i.e., one’s great-grandchildren, and the third generation from his wife’s son and his wife’s daughter, i.e., one’s wife’s great-grandchildren, are all forbidden as secondary forbidden relationships. So too, the fourth generation from his father-in-law and from his mother-in-law, i.e., his wife’s great-grandmothers, are prohibited as secondary forbidden relationships.

א"ל רבינא לרב אשי מאי שנא למעלה דקחשיב לה לאשתו ומאי שנא למטה דלא קחשיב לה לאשתו למעלה דאיסורא מכח אשתו קא אתי חשיב לה למטה דאיסורא לאו מכח אשתו קאתי לא קחשיב לה

Ravina said to Rav Ashi: What is different between the generations above, referring to his wife’s great-grandmothers, such that the Sage counts his wife as one of the generations and refers to them as the fourth generation, and what is different with regard to the generations below, referring to his great-granddaughters, such that he did not count his wife and referred to them as only the third generation? The Gemara answers: When counting above, the prohibition stems from his wife, as they are not his blood relatives but his wife’s. Therefore, she is counted. When counting below, however, the prohibition does not stem from his wife, as they are his own blood relatives, and so she was not counted.

והא בן אשתו ובת אשתו דאיסורא מכח אשתו קאתי ולא חשיב לה איידי דתנא שלשה דורות למטה דידיה ולא חשבה תנא נמי ג' דורות למטה דידה ולא חשבה

The Gemara objects: But he includes the granddaughter of his wife’s son and his wife’s daughter in his list of those forbidden due to his wife, yet he does not count her and refer to this as the fourth generation. The Gemara answers: Since he already taught three generations below himself, i.e., his own great-granddaughter, and there he did not count from his wife because it is his own blood relative, he taught three generations below his wife and did not count her. Instead, he referred to her great-granddaughter also as three generations below to maintain the uniform style of his words.

א"ל רב אשי לרב כהנא שניות דבי רבי חייא יש להן הפסק או אין להם הפסק

Rav Ashi said to Rav Kahana: Do those secondary forbidden relationships taught by one of the Sages of the school of Rabbi Ḥiyya have a conclusion, or do they not have a conclusion? Are those specified cases alone forbidden, or are all generations above and below also forbidden?

ת"ש דאמר רב ד' נשים יש להם הפסק ותו לא דלמא כי קאמר רב לההיא מתניתא ת"ש שלישי ורביעי שלישי ורביעי אין טפי לא דלמא משלישי ואילך מרביעי ואילך

Come and hear that which Rav said: Four women have a conclusion. This implies that it is only these four and no more. The Gemara rejects this: Perhaps when Rav said this he was referring only to the relationships listed in the baraita and not to all cases of secondary relationships. The Gemara suggests: Come and hear from the baraita itself, which states: The third generation from his son and his daughter and the fourth generation from his father-in-law and mother-in-law. This implies that with regard to the third and the fourth generations, yes, they are forbidden; but more than that, no. The Gemara rejects this: Perhaps this means from the third onward and from the fourth onward. The Gemara does not resolve this issue.

אמר ליה רבא לרב נחמן חזי מר האי מרבנן דאתא ממערבא ואמר בעו במערבא גזרו שניות בגרים או לא גזרו שניות בגרים

§ Rava said to Rav Naḥman: Did the Master see this one of the Sages who came from the West, Eretz Yisrael, who said: In the West they asked whether the Sages issued a decree prohibiting secondary forbidden relationships for converts, or whether they did not issue a decree prohibiting secondary forbidden relationships for converts?

אמר רב נחמן גרים הואיל ואתו לידן נימא בהו מלתא אחין מן האם לא יעידו ואם העידו עדותן עדות אחין מן האב מעידין לכתחלה אמימר אמר אפילו אחין מן האם נמי מעידין לכתחלה

Rav Naḥman said: Since the issue of converts and their relatives has come to hand and is the topic of discussion, let us say a matter of halakha: Maternal half brothers who both convert may not testify together as a pair of witnesses before the court, but if they did testify, their testimony is valid. Although blood relatives are invalid as witnesses, converts are considered as though they have no relations. Paternal half brothers who both convert may testify together ab initio, since the halakha does not consider paternal half brothers of gentiles to be true relatives. Ameimar said: Even maternal half brothers may also testify together ab initio.

ומ"ש מעריות ערוה לכל מסורה עדות לבית דין מסורה וגר שנתגייר כקטן שנולד דמי:

In what way is this case different from forbidden relations, where a convert may not marry his maternal sister due to rabbinic decree? The halakhot of forbidden relations are handed over to all, and every individual chooses his own wife. Therefore, the Sages issued a decree to prevent confusion between the status of a convert and that of a born Jew. However, testimony is handed over to the court, and the court knows to distinguish between the status of a born Jew and that of a convert. And the legal status of a convert who just converted is like that of a child just born, and all previous family ties become irrelevant.

מתני׳ מי שיש לו אח מכל מקום זוקק את אשת אחיו ליבום ואחיו הוא לכל דבר חוץ ממי שיש לו אח מן השפחה ומן העובדת כוכבים מי שיש לו בן מכל מקום פוטר אשת אביו מן היבום וחייב על מכתו ועל קללתו ובנו לכל דבר חוץ ממי שיש לו בן מן השפחה ומן העובדת כוכבים:

MISHNA: In the case of anyone who has a brother of any kind, that brother creates a levirate bond causing his yevama to be required to perform levirate marriage if the first brother dies childless. And he is his brother in all respects, except for one who has a brother born from a Canaanite maidservant or from a gentile woman, as these do not have the legal status of brothers. Similarly, in the case of anyone who has a child of any kind, that child exempts his father’s wife from levirate marriage, since his father did not die childless. And that child is liable to receive capital punishment if he strikes his father or curses him. And he is his child in all respects, except for whoever has a child born from a Canaanite maidservant or from a gentile woman, as these do not have the halakhic status of children.

גמ׳ מכל מקום לאתויי מאי אמר רב יהודה לאתויי ממזר פשיטא אחיו הוא מהו דתימא לילף אחוה אחוה מבני יעקב מה להלן כשרין ולא פסולין אף כאן כשרין ולא פסולין קמ"ל

GEMARA: The Gemara asks: With regard to the statement that a brother of any kind causes his yevama to be required to perform levirate marriage, what additional case does this come to add? Rav Yehuda said: This adds the case of a mamzer, who, notwithstanding his status, is considered a brother. The Gemara wonders: But isn’t that obvious? He is his brother. The Gemara explains: This is necessary lest you say: Let us derive a verbal analogy between the word “brother” stated in the verse with regard to levirate marriage and “brother” stated with regard to the children of Jacob. Just as there, Jacob’s children are of unflawed lineage and not of flawed lineage and are not mamzerim, so too here, one might think that only brothers of unflawed lineage and not brothers of flawed lineage, i.e., mamzerim, obligate the yevama in levirate marriage. Therefore, this teaches us that a mamzer is considered a brother for the purposes of levirate marriage.

ואימא הכי נמי כיון דלענין יבום מיפטר נפטר

The Gemara asks: And say that is indeed the halakha. Perhaps a brother who is a mamzer does not obligate his yevama in levirate marriage. The Gemara answers: Since with regard to levirate marriage, if the husband had a child who was a mamzer he would exempt the wife from levirate marriage,