If a man is a saris – a male eunuch who cannot have children – do the laws of yibum (levirate marriage) apply to him?
The Mishna on our daf brings a statement made by Rabbi Yehoshua that addresses this question, but leaves us in a state of confusion. Rabbi Yehoshua teaches that he has one tradition that teaches that a saris will perform halitza (ceremony releasing him from yibum) and that the widow of a saris should receive halitza, and another that teaches that in neither of those cases will halitza be necessary.
Although Rabbi Yehoshua does not have an explanation for those contradictory statements, other tanna’im in the Mishna do. Rabbi Akiva suggests that we should distinguish between a saris adam – someone who developed his condition though an injury or other outside force – and a saris hamah – someone who had this condition developmentally. In the former case, since the person at one period could have had children, the rules of yibum and halitza apply to him, while in the latter case, since he never could have children, these rules are not applicable. Rabbi Eliezer agrees that we must distinguish between these two cases, but he reaches the opposite conclusion. His reasoning is that a saris hamah may recover from his condition, so we should apply to him the rules of yibum, while a saris adam who has no chance of recovery cannot possibly have children, so yibum will not apply to him.
This dilemma is one that deals with one of the most basic questions about yibum. According to the Torah, the purpose of the mitzva of yibum is lehakim zera le-ahiv – for the surviving brother to have a child “on behalf” of the brother who has died. Nevertheless, we cannot possibly be certain that a married couple will succeed in having children together. Thus, all we can ascertain is that the possibility exists that a child can be born. The question that we are faced with in the case of a saris is, do we look at the likelihood of a future birth, or do we concern ourselves with making sure that the yavam is someone who, in his nature, was capable of fathering children.