- שלישי בראשון and שני בשני, שני בשלישי
Rav said: אחי אבא לא יעיד לי הוא ובנו וחתנו – My father’s brother cannot testify for me, neither he, nor his son, nor his son-in-law. אף אני לא אעיד לו אני ובני וחתני – I, too, cannot testify for [my father’s brother], neither I, nor my son, nor my son-in-law. This second statement, that a son (or son-in-law) cannot testify about a great-uncle, is שלישי בראשון – a third-generation relative testifying about a first-generation relative. The Gemara asks that our Mishnah only disqualifies שני בשני – a second-generation relative testifying about another second-generation relative, or a שני בראשון, but does not disqualify a third-generation relative from testifying about a first-generation!? The Gemara answers that Rav’s opinion, although it does not agree with the Mishnah, is based on Rebbe Elazar, who taught in a Baraisa that his cousin cannot testify about him, nor can his son or son-in-law, proving he does disqualify the testimony of a third-generation relative (a cousin’s son). The Gemara objects that Rebbe Elazar even disqualifies a שלישי בשני, since the cousin’s son cannot even testify about his father’s cousin!? The Gemara concludes that Rav partially agrees with Rebbe Elazar and partially disagrees. Their respective derashos are explained.
- A relative’s spouse is also a relative
The Gemara asks: מהו שיעיד אדם באשת חורגו – what is the halachah regarding testifying for one’s stepson’s wife about her property? [Rashi explains that one definitely cannot testify about the wives of the other relatives in the Mishnah, since he cannot testify about the sons of those relatives, who stand to inherit from their mother’s properties.] In Sura they said: בעל כאשתו – a husband is like his wife, therefore, any woman relative about whom he cannot testify (e.g., a stepdaughter), he also cannot testify about her husband. In Pumbedisa they said: אשה כבעלה – a woman is like her husband, so one may not testify about the wife of any man relative for whom he cannot testify (e.g., a stepson). Rav derives that a woman is like her husband from the Torah prohibiting relations with an uncle’s wife, calling her "דודתך" – “your aunt,” even though she is actually his uncle’s wife. This proves that a wife is like her husband.
- Testifying about one’s ארוסה wife
Rabbah bar bar Chanah said: מעיד אדם לאשתו ארוסה – a person may testify about his arusah wife, because he is not yet “related” to her. Ravina said this only applies to testifying to take away money from her, אבל לעיולי לה לא מהימן – but to bring money to her, he is not believed, since he knows the money will become his after נשואין. However, the Gemara says this is not so, and he is not believed either way regarding his arusah. Although Ulla taught that one’s arusah is not his wife for many halachos (such as mourning, becoming tamei for her burial, and inheritance), התם בשארו תלה רחמנא – there, the Torah hinged [these laws] on close relationship, which an arusah is not. In contrast, the disqualification of relatives’ testimony is משום איקרובי דעתא – because of closeness of feeling, and this closeness exists for an arusah.