1) AN OBJECT DEPOSITED BY A MINOR
OPINIONS: The Gemara states that one who received an item as a deposit from a minor should not return it to the minor, but rather he should sell the object and invest the money on behalf of the minor. The Gemara later states that this investment should be either a Sefer Torah or a palm tree, in order to preserve the minor's capital.
The Gemara continues and says that if a woman, slave, or minor deposited an object with someone to watch, and then the woman, slave, or minor specified on his or her deathbed to whom the object belongs, he or she is believed and the deposit should be handed over to the named owner.
(a) The RASHBA comments that the reason why an investment is made for the minor (and the object itself is not returned to him) is not that the child is not considered mature enough to take care of the object, but rather the one holding the object has an obligation "b'Yedei Shamayim" to perform the Mitzvah of returning the lost object in the best possible way. If he returns the object to the minor, he would not be obligated to compensate the minor for the loss if the minor later loses the object. In order to ensure that the minor receives and retains his property, it is invested for him and returned to him when he reaches adulthood.
The Rashba continues and says that the Gemara's statement that one should invest the money refers only to the money of a very small child, such as a child below the age of six, or one who has no idea of the meaning of buying and selling (see Gitin 59a). If, however, the child has already reached the age at which he understands the meaning of buying and selling, then the deposit should be returned to him because at this age children are actively encouraged to start learning about trade and are given objects with which they can trade. When a minor has reached the age at which he understands the meaning of buying and selling, his transactions of buying and selling are valid.
(b) The RASHBAM (DH Kibel) seems to disagree with the Rashba. He states that the reason why one should not return a deposit to a minor is that doing so is considered equivalent to throwing the object away, since the child does not know how to take care of the object. It seems that, according to the Rashbam, Beis Din may even force the guardian of the object to purchase an investment for the minor.
Also, the Rashbam states that even a minor is believed on his deathbed to identify the owner of the object. The KOVETZ SHI'URIM (#235) proves from this statement that the Rashbam does not agree with the Rashba. Since a minor under the age of six is not believed to identify the owner of the deposited object, the Gemara must be discussing a minor over the age of six. Hence, when the Gemara discusses investing the money of a minor, it must refer to investing the money of a minor over the age of six. The reason for this must be that even though the child at this age is capable of buying and selling, one should not rely on him to take care of objects until he reaches the age of adulthood (i.e. 13 for a male, 12 for a female). (Y. MARCUS)
2) ARTICLES WHICH ARE OFTEN LENT OR RENTED OUT
QUESTION: The Gemara discusses a case in which Reuven claims that a certain object in Shimon's possession belongs to him. Reuven brings witnesses who testify that they saw that the object once belonged to Reuven. If the object is the type of object that is frequently lent or rented to others, Shimon is not believed to say that he bought the object from Reuven and the object belongs to him. Beis Din assumes that Reuven lent or rented it to Shimon (unless Shimon proves otherwise).
This principle -- that a person cannot make a Chazakah on objects that are normally lent or rented out -- seems to contradict the Gemara in Shevuos (34a). The Gemara there teaches that when Levi hands over money to Yehudah in the presence of two witnesses, Yehudah is believed to claim later that he indeed received money from Levi but that money was the repayment of a loan from Levi. According to the principle presented by the Gemara here, in a case in which the witnesses do not know whether Yehudah was receiving a loan from Levi or whether he was receiving a repayment for a loan that he gave to Levi, Beis Din should assume that Yehudah was receiving a loan from Levi since money is something that is normally lent to others. Why does the Gemara there say that Yehudah is believed to say that the money he received was a repayment of a loan due to him?
(a) The KETZOS HA'CHOSHEN (79:2) distinguishes between money and objects. With regard to the lending of money, the principle of "Milveh l'Hotza'ah Nitnah" applies. This means that when the lender lends money, the borrower is allowed (and expected) to spend that money and to return different money of the same value to the lender. In contrast, when a person lends an object, the borrower is obligated to return the same object. The reason why objects that are frequently lent or rented out are not assumed to belong to the person holding them is that they are not considered to have left the possession of the original owner (Mara Kama) unless there is proof otherwise. Money, however, always leaves the possession of the Mara Kama, and afterwards the borrower must return different money. Hence, Yehudah, who is holding the money, is believed to say that it is his money because no Chezkas Mara Kama opposes him.
(b) RAV YITZCHAK ELCHANAN SPECTOR (cited by the MILU'EI CHOSHEN to the Ketzos ha'Choshen) gives another answer to this question. The SHULCHAN ARUCH (CM 72:19) cites the RIF and RABEINU TAM who rule that any object which the owner does not usually lend out because of its importance is not considered in the category of "objects which are normally lent out." Accordingly, money is not considered to be something that is normally lent out, because the owner is apprehensive about lending it because the borrower might not return it.
The Shulchan Aruch there also quotes the RAMBAM who rules that only objects which are made for the purpose of being lent or rented out fall into this category. According to this definition as well, money is not considered an object that is normally lent. (Y. MARCUS)