We were previously taught in the Mishna (Yevamot 3:1, 26a) about a case of four brothers, where two of them were married to two sisters, and then the two married brothers suddenly died without having fathered a child – with the question being whether the two remaining brothers may marry the two widowed sisters?
The answer is that because each woman is technically a potential yevama to both brothers, then such a marriage is rabbinically forbidden. Nevertheless, while yibum should not be performed in such a situation, halitzah is still required for both women. But the question then addressed in the Mishna (as well as in Mishna Eduyot 5:5) is what is the law if the parties involved ignored the rabbinic prohibition and chose to fulfil yibum where one or both women married their respective brother-in-law?
Rabbi Eliezer explains that Beit Shammai rule in such a case that the marriage may continue to be (i.e. while yibum should not have been done, once done then no efforts should be made to object against and end the marriage), while Beit Hillel rules that they must divorce. According to this version of the debate, Beit Shammai are more lenient, whereas Beit Hillel are more strict.
However, in today’s daf (Yevamot 28a) a Beraita is cited where Abba Shaul claims that these opinions were misattributed and that, ‘a lenient opinion was held by Beit Hillel in this matter whereby Beit Shammai [was actually the one who said] that they must divorce, whereas Beit Hillel [was the one who said] they may remain together’. And why? Because Abba Shaul did not think that the attributed opinions in the Mishna aligned with our overall knowledge of when Beit Shammai are lenient and Beit Hillel are strict. Meaning that his gut said that what he was reading didn’t ring true.
Interestingly, the Rambam in his commentary to the Mishna (Yevamot 3:1) appears to rule according to the position of Abba Shaul. However, in his Mishne Torah (Hilchot Yibum V’Halitzah 7:5) he rules according to the original text of the Mishna. As Rav Yosef Karo explains (in his Kesef Mishne commentary to the Rambam), having examined the topic further the Rambam later changed his mind.
What we can learn from here is that while there may be things that people say that seem so different to what we expect of them that our gut says that they couldn’t have said it, there are times when gut reactions are wrong and times when people say things that are simply unexpected.