1) THE NATURE OF AN ACQUISITION OF LAND DURING THE TIME WHEN "YOVEL" IS IN EFFECT
QUESTION: The Gemara cites a Beraisa which teaches that when the Yovel year arrives, any field that was purchased must be returned to its original owner, but the purchaser is not required to "return" the improvements that he made to the field (and thus when he returns the field, the original owner must pay him for the improvements). The Gemara attempts to derive from this law that when a sharecropper ("Mekabel") finishes his work, the owner of the land is similarly obligated to pay him for any improvements that he made to the land. The Gemara rejects the proof and explains that there is a basic difference between a buyer who must return a field when Yovel arrives, and a sharecropper (renter) who must return a field when the term of the rental ends. The buyer's purchase of the land is a valid, permanent sale, which gives him full ownership of the field. He must return the field only because Hash-m decreed that the Yovel annuls the sale and the field returns to its original owner. In the case of a rental, though, the field never leaves the possession of the original owner, and therefore the sharecropper is not entitled to receive payment for the improvements to the field.
(The MINCHAS CHINUCH (339:10) deduces from this Gemara that, at Yovel, the original owner does not need to make a new Kinyan to acquire the field, because Hash-m decreed that it should be returned to him and that the Kinyan of the buyer should be annulled.)
The Gemara here clearly indicates that the Kinyan of the buyer is a valid and complete Kinyan, and the Yovel is a special decree that returns the land to its original owner. This seems to contradict the Gemara in Gitin (48a). The Gemara there says that when one buys a field (when Yovel is in effect), his purchase is not a full purchase of the field, but rather it is a "Kinyan Peros" -- he acquires the field only with regard to the fruit that it produces, but the original owner still owns the "Guf" of the field. The Gemara there discusses whether a Kinyan Peros is considered a Kinyan ha'Guf or not. According to all opinions in the Gemara there, one who buys a field (when Yovel is in effect) acquires only the Kinyan Peros. The Gemara here, however, implies that the buyer has a complete Kinyan, and Yovel annuls the Kinyan and returns the field to the original owner.
ANSWER: The SHO'EL U'MESHIV (of RAV YOSEF SHAUL NATANSOHN, 4:3:58) answers that although the buyer has a full-fledged Kinyan, nevertheless the buyer's Kinyan is considered a Kinyan Peros because the Torah decrees that the field will be returned to the seller without a need for a new Kinyan. This means as follows. The Gemara in Gitin says that before the first Yovel year in history, people sold their lands with the absolute intention that the sale would be permanently binding. The first Yovel year activated the decree of the Torah that annulled the buyers' Kinyanim and returned the lands to their original owners. After the first Yovel, people knew that Yovel would return the fields to their owners and they therefore began to buy fields with the knowledge that the sale would last only until Yovel. Hence, their "Da'as" makes the Kinyan into a Kinyan Peros. (Y. MARCUS)
2) MAY A MOHEL RECEIVE PAYMENT FOR HIS SERVICES
OPINIONS: Rava rules that a teacher of young children, a professional field-planter, a butcher, an "Uman," and a "Safar Masa" (see following Insight) are all considered to be forewarned with regard to the proper execution of their tasks, since any mistake that they make will cause an irreversible loss. Consequently, if they err, they lose their positions without further warning.
When Rava mentions an "Uman," to what profession does he refer?
(a) RASHI interprets the word "Uman" as a reference to a Mohel. Rashi thus implies that a Mohel is permitted to receive payment for his services. This is because the law that Rava teaches here is relevant to financial matters; Rava teaches that these workers are removed from their positions and do not receive their outstanding pay. It is therefore clear that these positions are paid positions, because, otherwise, it would make no difference to the workers if they lose their work. Accordingly, it seems from the Gemara that the position of Mohel is a paid position.
(b) The YA'AVETZ does not agree with the apparent position of Rashi. He maintains that one is not permitted to receive payment for performing Milah. The RASHBA (in Teshuvos 1:475) writes that a Mohel who receives payment "is not acting in accordance with the proper conduct expected from a descendant of Avraham Avinu." He writes that it has always been understood, throughout the generations, that the father of a baby does the Mohel the greatest kindness by allowing him to perform the Milah. The Rashba concludes that Beis Din should admonish a Mohel who takes payment.
The YA'AVETZ therefore suggests that when Rava mentions an "Uman," he refers not to a Mohel but to a blood-letter ("Meikiz Dam"), as the term "Uman" refers to a blood-letter in a number of places throughout the Gemara.
The TOSFOS HA'ROSH also says that "Uman" refers to a blood-letter, as Rashi himself explains the word earlier (97a). (The HAGAHOS HA'GRA to Shulchan Aruch CM 306:21 says that both explanations of "Uman" here are true, since errors in both professions involve losses that cannot be corrected.) (Y. MARCUS)
3) A "SAFAR MASA"
OPINIONS: Rava rules that a teacher of young children, a professional field-planter, a butcher, an "Uman" (see previous Insight), and a "Safar Masa" are all considered to be forewarned with regard to the proper execution of their tasks, since any mistake that they make will cause an irreversible loss. Consequently, if they err, they lose their positions without further warning.
When Rava mentions a "Safar Masa," to what profession does he refer?
(a) RASHI earlier (97a) explains the term "Safar Masa" as a reference to the town barber. This is also one of the explanations of RABEINU YEHONASAN (cited by the Shitah Mekubetzes here), who explains that when a barber errs, although his victim's hair will eventually grow back, the customer nevertheless experiences intense embarrassment when too much hair was removed, and that constitutes an irreversible loss.
(b) RASHI in Bava Basra (21b) explains that a "Safar Masa" is a scribe, Sofer, who writes Sifrei Torah.
TOSFOS there asks, why is a Sofer's error considered an irrevocable loss? After all, if a Sofer makes a mistake in a letter in a Sefer Torah, it can be corrected with ease.
Tosfos there answers that when a Sofer makes a mistake in writing the Name of Hash-m, the mistake cannot be corrected. When the Gemara says that a Sofer's mistake causes an irrevocable loss, it refers to such a mistake.
The RAN and other Rishonim answer that the Gemara refers to a Sofer who makes five mistakes on a single parchment of a Sefer Torah. The Gemara in Menachos (29b) teaches that a parchment with five mistakes must be buried and cannot be used.
The MELO HA'RO'IM in Bava Basra answers that the Gemara refers to a Sofer who writes Tefilin and Mezuzos. Since the text inside of Tefilin and Mezuzos must be written in order, if he makes a mistake he cannot correct it and he must start anew.
The PNEI SHLOMO cited by the DEVAR YAKOV answers that the irreversible loss that results from the Sofer's mistake is that the Tzibur unknowingly reads from a Sefer Torah that is not valid.
(c) TOSFOS in Bava Basra (21a) and the ME'IRI explain a "Safar Masa" as a scribe who writes legal documents.