QUESTION: The Gemara quotes a Beraisa which states that a homeowner in a jointly-owned courtyard may not rent his house to a Mohel, a blood-letter, a wool-comber, or a non-Jewish elementary school teacher, if the other homeowners object. A person with one of these occupations who takes up residence in the courtyard causes a significant increase in the noise level in the courtyard because of the large number of people who come to seek his services.
Why does the Gemara prohibit only renting out one's house for those purposes? The Gemara should also prohibit selling a house to such people. (RASHASH)
(a) The RASHASH answers that it is obvious that selling a house to someone who will create a significant disturbance in the courtyard is prohibited. The Gemara wants to teach that even renting a house for such a purpose is prohibited, even though a rental might be for a short time. The Gemara teaches that even a temporary disturbance is also prohibited.
(b) The Rashash answers further that the MORDECHAI rules that one is permitted to sell a house for these purposes. The reason is that the neighbors always have the option to protest when the new owner begins to make noise in the courtyard, and they will be able to take him to Beis Din and force him to stop causing a disturbance. Since the neighbors have this recourse, one is not prohibited from selling the house in the first place. (According to this answer, if the buyer is not Jewish and will not agree to go to Beis Din, then the owner indeed may not be allowed to sell the house to him.)
Why does the same logic not apply to a rental? The owner should be permitted to rent out his house to anyone, and if the renter creates a disturbance, the neighbors will be able to take him to Beis Din.
The S'MA (CM 156:8) answers that when a person buys property, he does not always intend to use it immediately for his profession. A person may purchase property but not live in it until he retires from his profession, at which point he moves into the property. (He may allow a family member to live there in the interim.) Since it is not known whether the purchaser will use the house in a way that causes a disturbance, the sale is not a case of "Bari Hezeika" and the owner therefore cannot be prevented from selling it. If the buyer later decides to use the house for a noisy purpose, the neighbors can summon him to Beis Din at that point. In contrast, a person who rents property usually moves into the rented property immediately; a person is not likely to rent property and refrain from living in it. Therefore, renting a house to a person who practices a noisy occupation is "Bari Hezeika," and the owner is not allowed to rent out his house to such a person. (Y. MARCUS)


QUESTION: Rav Huna says that if a person who lives in a semi-public alley ("Mavoy") sets up a mill to grind flour, he has the right to prevent a neighbor from building a second mill. He can claim that the second neighbor will take away his customers (and thus his livelihood) if he sets up a second mill.
The Gemara attempts to prove Rav Huna's ruling from the law that if a fisherman has already found the hole in which a fish lives, he has the right to prevent other fishermen from spreading their nets, up to a radius of one Parsah from the hole, even though he has not yet caught the fish. This law seems to support Rav Huna's ruling that a person has the right to prevent others from taking away his potential livelihood.
TOSFOS (DH Marchikin) asks that the right of a fisherman seems to contradict the principle taught by RABEINU TAM concerning the Halachah of "Ani ha'Mehapech b'Chararah" (see Kidushin 59a). The Halachah of "Ani ha'Mehapech b'Chararah" states that if one person is trying to buy a certain object or obtain a certain job and a second person preempts him, the preemptor is considered a "Rasha." Rabeinu Tam maintains that if the second person preempts the first in picking up an object of Hefker, he has done nothing wrong and he is not considered a Rasha; since he would not have been able to acquire the object elsewhere, he is entitled to take it first.
According to Rabeinu Tam, why are the other fishermen not allowed to spread their nets? Even if one fisherman clearly began to attempt to trap a certain fish, the other fishermen should be permitted to trap it because the fish is Hefker, and they will not be able to find such a fish elsewhere.
TOSFOS in Kidushin (59a, DH Ani) answers in the name of RABEINU MEIR (the father of Rabeinu Tam) that in the Gemara's case of the fishermen, the first fisherman lowered into the water a dead fish which attracted all of the other fish. Since the first fisherman has performed an action to attract the other fish, his colleagues are not allowed to take those fish even though they are Hefker.
The KETZOS HA'CHOSHEN (273:4) challenges this answer from another Gemara in Kidushin. The Gemara in Kidushin (25b, according to the explanation of Tosfos there) explains how it is possible to acquire an elephant with a Kinyan of "Hagbahah" (lifting it up): the purchaser lifts tree branches above the elephant's head so that the elephant jumps up to eat them. Since the elephant raises itself as a result of the purchaser's action, it is considered as though the purchaser has done "Hagbahah" and lifted the animal, and thus he fully acquires the animal.
The Ketzos ha'Choshen reasons that according to this explanation, a fisherman who uses a dead fish to attract other fish makes a Kinyan on the fish. Just as the Kinyan of "Hagbahah" is accomplished when the purchaser causes the elephant to lift itself, a Kinyan of "Meshichah" should also occur when the fisherman places a dead fish in the water that causes other fish to move toward it. The fisherman should be considered to own the fish as a result. Why, then, does Tosfos say merely that if other fishermen take the fish, they are infringing on the first fisherman's livelihood? Since the first fisherman has already acquired the fish, the other fishermen who take them are committing an act of outright theft!
ANSWER: The NESIVOS HA'MISHPAT (273:3) answers that there is a distinction between a direct action and an indirect action on the part of the purchaser. In the case of the elephant, the purchaser can acquire the elephant only if he actually holds the tree branches at the time the elephant jumps up to eat them. If he has already let go of the branches, he only indirectly causes the animal to jump up, and he is not considered to be performing a Kinyan of "Hagbahah."
The Gemara in Kidushin (22b) says that if a person calls to an animal and thus causes the animal to come to him, he is considered as though he pulled the animal with his hands and it is a valid Kinyan of "Meshichah." That is because the owner did something which directly caused the animal to move toward him. In contrast, when the first fisherman places a dead fish in the water and then goes away, he does not directly cause the fish to come, and therefore he does not fully acquire the fish that come. If someone else then takes the fish, it is not considered an act of theft because the first fisherman did not own the fish in the first place. Rather, the person who takes away the fish is considered a "Rasha," for he encroaches on the first person's livelihood when he preempts him and captures the fish. (Y. MARCUS)