§ The Gemara resumes its discussion of the source for the disqualification of relatives from bearing witness. From the fact that the verse: “The fathers shall not be put to death for the children” (Deuteronomy 24:16), is not phrased in the singular, i.e., A father shall not be put to death for his child, it is derived that not only are a father and child disqualified from bearing witness about one another, but closely related relatives, i.e., brothers, are also disqualified from bearing witness about each other’s children. Consequently, we found a source for the disqualification of fathers from bearing witness about their children or the children of their brothers, and for the disqualification of children from bearing witness about their fathers or their fathers’ brothers.

And all the more so, the related fathers, e.g., brothers, are disqualified from bearing witness about each other, as they are certainly more closely related to each other than are a nephew and an uncle.

But from where do we derive that one brother’s children cannot bear witness about the children of the other brother?

The Gemara answers: If so, if the children of one brother can bear witness about the children of the other brother, let the verse write: The fathers shall not be put to death for the child. For what reason is “children” written, in the plural? It is derived from here that even children of brothers are disqualified from bearing witness about each other.

We found a source for the halakha that the children of brothers cannot bear witness about each other. From where do we derive that the children of brothers cannot bear witness together about others?

Rami bar Ḥama says: This halakha is based on logical reasoning, and is not derived from a verse. This is as it is taught in a baraita: The witnesses are not rendered conspiring witnesses unless they are both rendered conspiring witnesses. And therefore, if it enters your mind that related children are fit to bear witness together about others, a conspiring witness can be found to be executed based on the testimony of his brother, i.e., his relative. Since a conspiring witness is executed for his testimony only if his co-witness is also rendered a conspiring witness, the testimony of his co-witness, who is a relative, is what causes him to be executed. This is tantamount to relatives bearing witness about each other. Therefore, relatives cannot serve as witnesses together.

Rava said to him: But according to your reasoning, there is a difficulty arising from that which we learned in a mishna (Bava Batra 56b): If one occupied land for three years, this serves in court as proof that he is the legal owner. If three brothers testify to his three-year possession of the land, with each one testifying separately about one year, and one unrelated individual joins with each of the brothers as the second witness, these are considered three distinct testimonies and are therefore accepted by the court. If they were to be considered one testimony it would not be accepted, as brothers may not testify together. But they are considered one testimony for the purpose of rendering them conspiring witnesses. In other words, they are punished only if all six of the witnesses are rendered conspiring witnesses, and the liability is divided among them.

Rava states his objection: If so, a conspiring witness can be found to be paying money due to the testimony of his brother, and nevertheless, the brothers’ testimony is not disqualified.

Rather, this is clearly not considered tantamount to brothers bearing witness about each other, as the rendering of one as a conspiring witness comes not from his co-witness but from others, i.e., the witnesses who testify that he had been with them. Here too, it cannot be proven logically that relatives are disqualified from bearing witness together, as the rendering of one as a conspiring witness comes from others.

Rather, the halakha that relatives are disqualified from bearing witness together is derived from a different source: If it is so that relatives can bear witness together, let the verse write: And a child shall not be put to death for the fathers, or: They shall not be put to death for the fathers. For what reason is “and the children” written in the plural? This indicates that related children are disqualified from bearing witness even about others.

The Gemara asks: We found a source for the disqualification of paternal relatives. From where do we derive the disqualification of maternal relatives? The Gemara answers: The verse states “fathers,” “fathers,” i.e., it states the word twice. This repetition is unnecessary, as the verse could have stated: And the children shall not be put to death for them. If the superfluous word “fathers” is not needed to teach the matter of paternal relatives, as this matter was already derived from the verse, apply it to the matter of maternal relatives.

The Gemara asks: We found a source for the halakha that one cannot bear witness to the detriment of his relative, as the verse states: “Shall not be put to death.” From where do we derive that one cannot testify to the benefit of his relative?

The Gemara answers: The verse states the term “shall not be put to death,” “shall not be put to death,” twice. If it is not needed to teach the matter of testimony to the detriment of one’s relative, as this halakha was already derived from the verse, apply it to the matter of testimony to the benefit of one’s relative.

The Gemara asks: We found a source for the disqualification of relatives in cases of capital law, as the verse is referring to execution. From where do we derive this halakha in cases of monetary law?

The Gemara answers that the verse states: “You shall have one manner of law” (Leviticus 24:22), which is interpreted to mean: A law that is equal for you. In other words, monetary law and capital law essentially follow the same guidelines.

§ Rav says: My paternal uncle will not testify about me, neither he, nor his son, nor his son-in-law, in accordance with the ruling of the mishna. Furthermore, I will not testify about him, neither I, nor my son, nor my son-in-law.

The Gemara asks: And why, for example, can Rav’s son not testify about the brother of his father’s father? But it is the testimony of a member of the third generation with regard to a related member of the first generation, as there is a two-generation difference between them. And we learned in the mishna that a member of the second generation cannot testify about a member of the second generation, e.g., one cannot testify about the son of his paternal uncle. We also learned that a member of the second generation cannot testify about a member of the first generation, e.g., one cannot testify about his uncle. But we did not learn that a member of the third generation cannot testify about a member of the first generation.

The Gemara answers: In the statement that is taught in the mishna: They themselves, and their sons, and their sons-in-law are considered relatives, what is the ruling of the mishna concerning his son-in-law referring to? It is referring to the son-in-law of his son. Accordingly, the mishna disqualifies the testimony of a member of the third generation about a member of the first generation.

The Gemara asks: But if so, let the mishna teach: And his son and the son of his son, instead of: His son-in-law. This would be a more straightforward manner of conveying the halakha with regard to a member of the third generation testifying about a member of the first generation.

The Gemara answers: By mentioning his son-in-law, the mishna teaches us a matter in passing: That with regard to the different levels of familial relationships, a husband is like his wife. Therefore, there is no difference between one’s son and one’s son-in-law.

The Gemara asks: But if the mishna is referring to the son-in-law of his son, a difficulty is posed by that which Rabbi Ḥiyya teaches in a baraita: Eight fathers, i.e., eight principal relatives mentioned in the mishna, are disqualified, which are twenty-four including the son and son-in-law of each. If the mishna is referring to one’s grandson these are thirty-two, as the son, the son-in-law, and the grandson of each are included.

The Gemara consequently rejects the explanation that the mishna is referring to the son-in-law of one’s son: Rather, the mishna is in fact referring to his actual son-in-law. And why does Rav refer to him as the son-in-law of his son, deriving from this case that a member of the third generation cannot testify about a member of the first generation? Since one’s son-in-law comes from outside the family he is considered a more distant relative than his son, as if he belongs to another generation.

The Gemara challenges this: If that is so, then the testimony of an individual with regard to the son-in-law of his father is equivalent to that of a member of the third generation with regard to a member of the second generation. And Rav is known to have deemed a member of the third generation fit to bear witness about a member of the second generation.

Rather, Rav stated his ruling not in accordance with the mishna, but in accordance with the opinion of Rabbi Elazar, as it is taught in a baraita that Rabbi Elazar says: Just as my paternal uncle will not testify about me, neither he, nor his son, nor his son-in-law, so too, the son of my paternal uncle will not testify about me, neither he, nor his son, nor his son-in-law. Accordingly, one cannot testify about the grandchild of his brother.

The Gemara asks: But still, according to Rabbi Elazar, the grandson of one’s uncle cannot testify about his great-great uncle, which is the testimony of a member of the third generation about a member of the second generation; and Rav deemed a member of the third generation fit to bear witness about a member of the second generation.

The Gemara answers: Rav holds in accordance with Rabbi Elazar’s opinion in one case, i.e., he disqualifies testimony of a member of the third generation with regard to a member of the first generation, and he disagrees with him in one case, i.e., he does not disqualify the testimony of a member of the third generation about a member of the second generation.

What is the reason for the opinion of Rav? It is as the verse states: “The fathers shall not be put to death for the children, and the children shall not be put to death for the fathers.” The phrase “for the children, and the children” is interpreted to include another generation, the grandchildren of one’s brother; they are also disqualified.

And Rabbi Elazar derives his opinion from the fact that the Merciful One states: “For the children,” which is interpreted to mean that the ones disqualified from bearing witness about the fathers are cast on the children as well. In other words, anyone who is disqualified from bearing witness about a father is also disqualified from bearing witness about his children.

§ Rav Naḥman says: The brother of my mother-in-law will not testify about me; the son of the brother of my mother-in-law will not testify about me; the son of the sister of my mother-in-law will not testify about me. And the tanna of the mishna also taught this halakha: His sister’s husband, and the husband of his father’s sister, and the husband of his mother’s sister, and his mother’s husband, and his father-in-law, and his brother-in-law, they themselves, and their sons, and their sons-in-law. This describes the same familial relationship from the perspective of the younger generation.

Rav Ashi said: When we were in Ulla’s study hall, we were asked: With regard to testifying about the brother of one’s father-in-law, what is the halakha? With regard to the son of the brother of one’s father-in-law, what is the halakha? With regard to the son of the sister of one’s father-in-law, what is the halakha?

And Ulla said to us: You learned the answer to this question in the mishna: His brother, and his paternal uncle, and his maternal uncle, and his mother’s husband, and his father-in-law, and his brother-in-law, they themselves, and their sons, and their sons-in-law. These relationships are the same as those you were asked about, from the perspective of the younger generation.

Rav arrived at a certain place to buy