- מתנת שכיב מרע שכתוב בה קנין
The Gemara discusses: מתנת שכיב מרע שכתוב בה קנין – the gift of a שכיב מרע with a kinyan written into it, where they performed a קנין סודר on the gift when it was not required. Rav says: ארכביה אתרי ריכשי – he has made it ride on two steeds, but Shmuel says: לא ידענא מאי אדון בה – I do not know how to judge [such a gift]. Rav holds that the שכיב מרע’s purpose in making a kinyan for his gift was to give it both the power of a מתנת שכיב מרע and of an ordinary gift: It is like an ordinary gift, in that he cannot retract upon recovering, and it is like a מתנת שכיב מרע, that it has the ability to transfer a loan. Shmuel says he does not know how to judge this gift, because שמא לא גמר להקנותו אלא בשטר – perhaps he only decided to transfer [the gift] to him with a document, ואין שטר לאחר מיתה – and a document cannot take effect after his death.
- מיפה את כחו
The Gemara asks that both Rav and Shmuel contradict their opinions above, because if a שכיב מרע said: כתבו ותנו מנה לפלוני – “Write a שטר and give a maneh to Ploni,” and died, Rav ruled we do not write it and give it, because perhaps he only intended to give it with a שטר, which is not effective after his death. Shmuel ruled that the gift should be written and given in this case!? The Gemara explains that the reason Rav ruled the gift ineffective here is דלא קנו מיניה – because in this case, they did not make a kinyan with him. Shmuel, who ruled the gift is effective in this case, does not contradict his previous ruling because this case is במיפה את כחו – where he was enhancing [the recipient’s] power with the kinyan, by explicitly saying so. Similarly, Rav Nachman interpreted another case where Shmuel validated a מתנת שכיב מרע made with a kinyan, as being a case of מיפה את כחו. Rav Chisda says that an example of such an expression is where they wrote: וקנינא מיניה מוסיף על מתנתא דא – “And we the witnesses made an acquisition of the gift from him in addition to his verbal instruction for this gift.”
- If a שכיב מרע wrote away his property and gave over the שטר, and then did so to a second person
Another machlokes between Rav and Shmuel is quoted: כתב וזיכה לזה – If he wrote away his property to someone and gave him [the שטר] recording the gift, and then did the same for someone else, Rav says the first recipient acquires it, and Shmuel says the second recipient acquires it. Rav’s ruling reflects his opinion that making a kinyan for the gift is meant to give it the power of a מתנת בריא; he holds giving over the שטר has the same effect, so he can no longer retract. Shmuel’s ruling reflects his opinion that this remains a standard מתנת שכיב מרע, and he can retract from it. The Gemara explains why Rav and Shmuel repeated their machlokes in this case. In Pumbedisa, Shmuel’s ruling was quoted in a different case, where a שכיב מרע wrote away his property and gave the שטר to the recipient, וקנו מידו – and additionally, [the עדים] made a kinyan from him for the gift, and Shmuel ruled: אין אחר קנין כלום – there is nothing that can undo a gift after a kinyan was made, since it was done after handing over the שטר.