Among the various cases recorded in the Mishna (Yevamot 9:2) in today’s daf (Yevamot 84a) are cases of women ‘who are permitted to marry their Yavam but who were forbidden to be married to their husband’. Specifically, this refers to instances where the Torah forbids certain men from marrying certain women (eg. a Kohen Gadol who is not permitted to marry a widow) such that, upon the death of their husband who was not blessed to have a child with them, these women may nevertheless fulfil Yibum with his brother (presuming that the brother does not have the same status has the deceased husband – eg. he is not the Kohen Gadol).
Reflecting on this Mishna, Rabbi Yehuda Leib Ginzburg explains in his ‘Mussar HaMishna’ that this law contains a ‘chiddush’ (i.e. a bold and original teaching). This is because an explicit intention of the law of Yibbum is the hope that this will lead to the birth of a child who will ‘perpetuate the name of the dead brother’ (Devarim 25:6). He therefore explains that what we learn from our Mishna is that even if the deceased brother was married to a woman that the Torah forbade him to marry – meaning that his marriage testified to him not observing all the laws of the Torah, the law of Yibbum – which strives to perpetuate his name – nevertheless applies. In fact, as Rabbi Ginzburg notes, the Shulchan Aruch (Even HaEzer 157:5) goes so far as to rule that if a man is an apostate and dies without children, then the law of Yibbum also applies to his widow.
What we learn from here is that even those who make choices that are not fully aligned with the Torah and may even be in direct conflict with core values of the Torah, deserve opportunities for their name to be perpetuated. Thus the law of Yibbum is not just a ‘preservative’ mitzvah to maintain the name of the deceased husband, but also a ‘redemptive’ mitzvah to enhance the name of the deceased husband. In short, Yibbum is about giving life to a name after its death, with the hope that it will not be forgotten.