QUESTION: The Gemara discusses a case wherein a person tells witnesses to write a Shtar (of transfer of property), sign it, and give it to someone. If the owner made a Kinyan with the witnesses for the transfer of the property, they may just write and sign the Shtar and hand it over to the new owner. If the owner did not make a Kinyan with the witnesses, then they must ask the owner again for his consent before they actually transfer the property by giving over the Shtar.
If the owner already told them to write, sign, and give over the Shtar, then why do they have to ask him again before giving over the Shtar? If the person wants to change his mind, he would come and tell us that he has changed his mind! Why do we have to suspect that he changed his mind?
(a) The ROSH (5:4) explains that since the person did not make a Kinyan Chalifin to transfer ownership of the property immediately, but rather asked that a Shtar be written to transfer ownership at the time of the delivery of the Shtar, it shows that he is reluctant to part with his property. Had he made a Kinyan Chalifin through the witnesses, the witnesses would have acquired the property on behalf of the recipient and it would have belonged to the recipient immediately. Instead, he told the witnesses to write a Shtar and to give the Shtar to the recipient in order to give him the land. Since the owner demonstrated reluctance in parting with his land, the witnesses must confirm with him before giving over the Shtar and finalizing the Kinyan. This might be the intention of TOSFOS (DH Kesuvu) as well.
(b) The RITVA, quoting the RA'AVAD (see Ra'avad in Hilchos Malveh v'Loveh 11:1), explains the Gemara differently than Rashi. The Gemara is not discussing someone who is giving land to his friend with a Shtar. Rather, the Gemara is discussing a husband who is writing to his wife a Tosefes for her Kesuvah. The husband is saying to witnesses at the time of Erusin that they should write the Tosefes in the Kesuvah at the time of Nisu'in. Since he does not tell the witnesses to write the Tosefes to his wife right now, at the time of Erusin, he shows that he is reluctant to give away his land to her as a Tosefes to her Kesuvah, and therefore they must ask him for his consent again at the time of Nisu'in. If he obligates himself to give his wife the Tosefes immediately at the time of Eirusin, by having the witnesses make a Kinyan on the Tosefes on behalf of the wife, then the husband does not have to be consulted again before writing the Tosefes in the Kesuvah and delivering it to his wife.
According to this explanation, it is clear why the Gemara records this case in this Sugya which discusses various aspects of the Kesuvah. (The GE'ONIM, in a Teshuvah cited by the Shitah Mekubetzes, give a similar explanation.)
(c) The RAMBAM (Hilchos Malveh v'Loveh 11:1) explains that the Halachah recorded in the Gemara refers exclusively to a borrower who is giving a Shtar Chov, a voucher for a loan, to his friend. There is a significant difference between a loan made without a Shtar and a loan made with one. When one borrows money without giving a Shtar to the lender, then if the lender demands repayment of the loan after the borrower paid it back, the borrower can simply reply that it was paid and he does not need to prove it. On the other hand, when one borrows money and gives a Shtar to the lender, if the lender wants to collect the money using the Shtar after the borrower paid it back, the borrower will have to bring proof that he already paid back the loan.
It is possible that according to the Rambam, we require that the borrower confirm his request to deliver the Shtar because he might not have taken into account all of the ramifications of this act. He might not have considered that if he gives a Shtar to the lender he will have to prove that the loan was repaid. Therefore, the witnesses must ask his consent again before giving over the Shtar.
The Rambam explains that when the Gemara says that if a Kinyan was made with the witnesses, they do not have to ask him again before giving over the Shtar, it means as follows. If the borrower made a Kinyan with the witnesses to obligate himself to give his friend a certain sum of money, then it is assumed that he wants them to write it down -- for a Kinyan performed before witnesses is presumably done with intention to have it written down (like Rashi says).
(d) The HAGAHOS MAIMONIYOS (Hilchos Malveh v'Loveh 11:1, #2) writes in the name of RABEINU TAM that the Halachah of our Gemara applies whenever a person gives his friend a gift. Basing himself on the Yerushalmi, he says that if a person asks a Shali'ach to give a gift to someone else, the Shali'ach must ask for the giver's confirmation before giving the gift, in order to make sure that the giver was serious (since he is giving something away without receiving any compensation for it).