1) THE "KINYAN" ACHIEVED BY A RENTED "CHATZER"
OPINIONS: The Mishnah (101b) states that when one rents a house, the Zevel that falls into the Chatzer of the house belongs to the owner and not to the tenant. The Gemara explains that the case of the Mishnah cannot be one in which the Chatzer (and not only the house) is rented by the tenant and the Zevel comes from the tenant's own animals, for in that case the Zevel certainly belongs to the tenant. The case of the Mishnah also cannot be one in which the Chatzer is not rented out and the Zevel is from the animals of the owner, because in such a case it is obvious that the owner keeps the Zevel, and it is unnecessary for the Mishnah to teach this. The Gemara therefore asserts that the Mishnah's case is one in which the Chatzer is not rented by the tenant and the Zevel that falls into it comes from animals that belong to other people.
What is the law in the case of a Chatzer that is rented by a tenant? For whom does the Chatzer acquire objects of Hefker that fall into it, the owner or the tenant?
(a) According to Rashi's Girsa in the Gemara, the Mishnah refers to a case in which the tenant rented only the house and not the Chatzer, and, accordingly, the Chatzer acquires the Zevel for the owner. This implies that if the tenant had rented the Chatzer, he would have acquired the Zevel. Thus, Rashi's version of the Gemara indicates that a rented Chatzer acquires objects of Hefker for the tenant and not for the owner.
(b) The RAMBAM (Hilchos Sechirus 6:5) understands the Gemara differently. According to the Rambam, the Gemara means that in the case of the Mishnah the Chatzer was rented out, but the owner of the Chatzer still acquires objects of Hefker that fall into it. The Rambam maintains that a rented Chatzer is Koneh for the owner, not for the tenant. The VILNA GA'ON, KETZOS HA'CHOSHEN, and other Acharonim question the Rambam's ruling from a number of Gemaras which seem to support the opinion of Rashi (see commentaries to Shulchan Aruch CM 313:3). (Y. Marcus)

102b----------------------------------------102b

2) A DISPUTE OVER THE THIRTEENTH MONTH OF THE YEAR
QUESTION: The Mishnah mentions an incident in which a tenant agreed to rent a property "for twelve gold pieces for the year, one Dinar per month," and the year was subsequently made into a leap year with thirteen months. The Gemara explains that such a case involves a contradiction in the terms of the rental. According to the first phrase ("for twelve gold pieces for the year"), the tenant should not be required to pay an additional gold piece for the extra month since the extra month is part of the year. According to the second phrase ("one Dinar per month"), the tenant should be required to pay an extra Dinar for the extra month. Rav Nachman (whom the Halachah follows) rules that the tenant must pay for the extra month, even if he has already lived there for that extra month. Rav Nachman's reasoning is that since the property itself (the rented house) belongs to the owner, the owner is considered to be the one who is "Muchzak" in this case. Since he has a Chazakah that the house is his, the tenant is not entitled to live there without paying the additional fee.
Why, though, should the ownership of the property be the deciding factor? The dispute is not about who owns the house, but rather about whether the tenant owes the rental money for the additional month. Since the tenant is in possession of that money, he should be considered "Muchzak" and he should not have to pay!
ANSWER: The KUNTRUS HA'SEFEIKOS (at the end of the Sefer) explains that in any case of a Safek in which Beis Din rules based on who is "Muchzak," the Muchzak is determined based on the moment when the Safek began. In this case, the Safek began at the end of the twelfth month. The owner claims that the rental agreement was for "one Dinar per month." According to his claim, every month is a separate rental period, and the tenant therefore is entitled to enter the house for the thirteenth month only on condition that he pays a thirteenth payment. According to the tenant's claim that the rental agreement was for "twelve gold pieces for the year," the original rental period (one year) has not yet terminated; it will end only at the conclusion of the thirteenth month. Therefore, the dispute between the owner and the tenant deals with whether or not the tenant may enter the house for the thirteenth month. Since the dispute involves the use of the house, the owner is considered the "Muchzak" since he is in possession of the house.
(According to this explanation, Rav Nachman's ruling applies only in a case where the subject of the dispute is Karka, such as a house or a field. Regarding whether his ruling also applies to Metaltelin, see Insights to 103:1, which mentions that Tosfos in this Sugya (103a) and Tosfos in Bava Basra (61b) argue about this point.) (Y. Marcus)