As we have learned, matnat shekhiv mera is a present given by an individual who is on his death bed. Unlike other examples of property transfer where the most basic requirement demands that a formal kinyan – an act of transfer – take place, in the case of matnat shekhiv mera the Sages ruled that no such kinyan is necessary. This rule was established in order to ease the concerns that rest on a dying person who wants to be sure that his will is carried out prior to his death. Nevertheless, there are restrictions to this unique rule of matnat shekhiv mera; according to the Mishna (146b), this gift 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, which leads to one final rule that applies to a case of matnat shekhiv mera – in the event that the dying man recovers, all of these presents must be returned, since they were given under a mistaken impression.
On our daf Rav Aḥa bar Minyumi quotes Rav Naḥman as ruling that even if someone on his deathbed gave away all of his property, he will not get it back if he recovers, since we suspect that he may have property in another place that he did not give away. According to this ruling, the Mishna’s teaching that he will get his property back if he recovers is limited to specific cases:
According to Rav Ḥama, only where his instructions stated clearly “I am giving away all of my property”, or
According to Mar bar Rav Ashi, where we are fairly certain that he has no other property.
Rav Naḥman’s ruling appears odd. Why would we suspect that someone is holding property that we don’t know about, and use that suspicion to keep him from getting his property back? The rishonim offer different suggestions that limit this halakha. The Ra’avad suggests that it is true only if he gave away his property in a manner that implies that he might have other property. Rav Avraham Av Beit Din says that it applies in a case where he specified the assets that he gave away, which indicates that it is likely that he owns additional assets not included in the gift.