As we have learned, according to the Mishna (146b), the unique power of the gift of a shekhiv mera – someone on his death bed – to take effect even without a formal kinyan, only works if the dying man bequeaths all of his possessions while on his death bed. This clarifies to us that he is only distributing his wealth because he assumes that he has no more need for physical possessions. Therefore, in the event that the dying man recovers, all of these presents must be returned, since they were given under a mistaken impression.
The Gemara on today’s daf brings a case where the witnesses who heard the dying man’s wishes write that he stated the gifts that he wanted to give while he was “sick in bed.” Their testimony did not state clearly, however, that he passed away from this illness, which is the ordinary language that is included in such documents when the witnesses are sharing their testimony that we are dealing with a case of matnat shekhiv mera. After the man died, his sons, who are interested in receiving their inheritance, claim that he enjoyed a brief recovery from that first illness, and that he retracted the gifts given while he was ill. Tosafot point out that the recovery in-and-of-itself undoes the matnat shekhiv mera, even if he did not say that he was retracting the gift.
Rabba says that the current situation – the man is dead and buried – appears to indicate that the matnat shekhiv mera remains in effect.
Abaye points to another case of doubt – when a ship sank and we do not know the fate of the people who were on the ship – where we assume that they are still alive unless we find proof to the contrary. Thus we do not always work with the current situation; we often prefer to assume that the earlier situation remains – especially since most people who are sick do recover.
The Gemara does not record a response to Abaye’s question. The Rosh suggests that from the continuation of the Gemara it appears that Rabba retracted his position; the Ramban suggests that this case is different, since we have the written testimony of the witnesses that at least superficially appears to clarify the situation for us – that he died of the illness, and that the matnat shekhiv mera should take effect.