Sanhedrin

We have thus found that 'fathers'  [cannot testify] for the sons [of each other], and vice versa; and all the more, 'fathers' [cannot testify] in respect of each other.  But whence is derived [the inadmissibility of] 'sons' [to give evidence] in respect of 'sons'?  — If so [sc. that such evidence is admissible], the text should have read, The fathers shall not be put to death on account of [the evidence of] a son.  Why 'sons'?  [To teach] that they too [are ineligible] in respect of each other. Thus we have found that 'sons' [are inadmissible] for each other. Whence do we know their inadmissibility [as joint witnesses] concerning others?  — Said Rami b. Hama: It is deduced by logic. For it has been taught: Witnesses cannot be declared Zomemim  until both are proved Zomemim.  Now, should you think that kinsmen  are eligible [to testify in cases] concerning strangers, a witness declared a Zomem  might suffer death because of his brother's evidence [which supported his own].  Raba demurred: But according to your argument, what of that which we learnt: If three brothers are [separately] supported by another witness,  they count as three separate sets of witnesses. But they count as one set in respect of being proved Zomemim.  It thus results that the perjured witness must pay money on account of the evidence given by his brother?  Hence [it must be assumed that the penalty for] false testimony is brought about through outsiders;  so here too, [the penalty for] false testimony comes about through strangers!  — But if so,  the text should have read: and a son on account of fathers, or, and they on account of the fathers. Why and sons? — To show that 'sons'  [are not eligible] in respect of strangers. We have thus deduced [the exclusion of] paternal relations. Whence do we know [the same] of maternal relations? — Scripture says, 'fathers' twice.  Since [the repetition] is unnecessary in respect to paternal relations, we may refer it to maternal relations.  Now, we have thus learnt [the exclusion of relatives' evidence] for condemnation.  Whence do we know [the same] of acquittal? — Scripture states, they shall be put to death, twice. Since that [the repetition] is unnecessary in respect of condemnation, refer it to acquittal. Again, we have learnt [the exclusion of relatives] in capital cases. Whence is the same known of civil suits? — Scripture says, Ye shall have one manner of law,  meaning that the law must be administered similarly in all cases. Rab said:  My paternal uncle, his son and his son-in-law may not bear testimony for me;  nor may I, my son nor my son-in-law testify for him. But why so? Does not this involve relationships of the third and the first degrees?  whereas we learnt that a relative of the second degree  [may not testify] for a relative of the second degree; and also that one of the second degree cannot testify for one of the first;  but not that a relative of the third degree may not bear testimony for one of the first? — What is meant by HIS SON-IN-LAW, stated in the Mishnah, is the son-in-law of his [the uncle's] son.  But should he not include [instead] his [the uncle's] grandson?  — He [the Tanna] teaches us incidentally that the husband bears the same relationships as his wife.  But what of that which R. Hiyya taught: [The Mishnah enumerates] eight chief relations  who make up the number of twenty-four.  But these [on the assumption that a son-in-law of the uncle's son ranks as a relative of the third degree] amount to thirty-two!  — But in fact, SON-IN-LAW is literally meant.  Why then does he [Rab] designate him the son-in-law of his [the uncle's] son?  — Because since his relationship comes from without,  he is regarded as one degree further removed.  If so, it is a case of the third degree vis a vis the second  [which is forbidden], whereas Rab allowed [the testimony of] the second degree to the third!  — But Rab agrees with R. Eleazar.  For it has been taught: R. Eleazar said: Just as my paternal uncle, his son and son-in-law may not testify for me so the son of my paternal uncle, his son and son-in-law may not testify for me. But still, that includes relatives of the third and the second degrees,  whereas Rab permitted the testimony of such relatives!  — Rab agrees with R. Eleazar in one point,  but differs from him in another. What is Rab's reason? — Scripture states, Fathers shall not be put to death for sons ['al banim]; and sons … :  this [the 'and'] teaches the inclusion of another generation [as ineligible to testify]. And R. Eleazar?  — Scripture states, 'al banim,  implying that the fathers' disqualification is carried over to the sons. R. Nahman said: My mother-in-law's brother, his son, and my mother-in-law's sister's son, may not testify for me. The Tanna [of the Mishnah] supports this: A SISTER'S HUSBAND; THE HUSBAND OF ONE'S PATERNAL OR MATERNAL AUNT, … ALL THESE WITH THEIR SONS AND SONS-IN-LAW [ARE INELIGIBLE AS WITNESSES]. R. Ashi said: While we were with 'Ulla,  the question was raised by us: What of one's father-in-law's brother, the father-in-law's brother's son, and the father-in-law's sister's son? — He answered us: We learnt this: A BROTHER, FATHER'S BROTHER, AND MOTHER'S BROTHER … ALL THESE WITH THEIR SONS AND SONS-IN-LAW [ARE INELIGIBLE]. It once happened that Rab went to buy