On this daf, we find a case where one need not do chalitzah or yibum.
When a certain woman who had not had children with her husband was slated to require yibum by her deceased husband’s brother, the local rabbonim arranged a posthumous divorce.
When the question of whether this was valid was presented to the Mahari ben Lev, he gave the following response:
“Regarding the divorces that certain sages gave to women by proxy after the decease of their husbands…I couldn’t believe what I heard. How can this sin be atoned for? …The Torah girds sackcloth over such actions and the altar sheds tears. I cannot fathom how people who were considered to be upstanding and learned could have made such a great error…for even children know that one may not divorce after death. This is a clear Mishnah and the commentators are explicit that no language allows posthumous divorce.”
The Mahari ben Lev continued: “I thought that perhaps her yovom was an apostate. Since some authorities hold that she need not receive chalitzah from such a yovom, it may have been possible to combine this leniency with the opinions of those who hold that one may divorce posthumously using certain language and consider her a divorced woman. Although I do not subscribe to this reasoning, at least it would be possible to understand the rabbonim who rendered this decision. However, after investigating the matter, I have found that her deceased husband’s brother is a far cry from an apostate. I urge you, therefore, to send this woman to us here. We will evaluate this situation and decide what to do.” (Shu”t Mahari ben Lev M’Eliyahu 1:31).