1) THREE PEOPLE OVER WHOM THE YETZER HA'RA HAD NO DOMINION
QUESTION: The Gemara states that "over three people the Yetzer ha'Ra had no dominion" -- Avraham, Yitzchak, and Yakov, and some say even David ha'Melech.
If the Yetzer ha'Ra had no control over them, then how could they receive reward in Olam ha'Ba for the Mitzvos that they did in this world? Without the influence of the Yetzer ha'Ra, there is no option but to choose to do good, so they would have had no Bechirah, free choice. How, then, could they be rewarded for doing good?
ANSWER: TOSFOS explains that their Yetzer ha'Ra was not entirely curtailed. Rather, since Hash-m saw that they made great efforts to avoid sin, Hash-m helped them and did not let the Yetzer ha'Ra influence them. This is based on the Gemara in Yoma (38b) which derives from the verse, "He guards the feet of His righteous ones" (Shmuel I 2:9), that once a person lives a majority of his life without sin, he receives Divine assistance and is able to live the rest of his life free of sin.
The BIRKAS AVRAHAM explains this further based on the words of the RAMBAM in Hilchos Teshuvah (6:2). The Rambam reconciles the verse, "And I will harden his (Pharaoh's) heart" (Shemos 4:21), with the concept of free will. The Rambam explains that Pharaoh had the power of free will, but he used that power to choose to sin and oppress the Jewish people. Once he sinned, Hash-m hardened his heart and took away his ability to choose to do good. The same principle, in converse, is evident in the Gemara here. The Gemara teaches that if a person always defeats his Yetzer ha'Ra and chooses to do good, he merits Divine assistance to the extent that, in the future, Hash-m will remove from him the urge to do evil and in effect will take away his Bechirah, his free will. However, a person who reaches this level is rewarded even for the removal of his free will, since it is a result of his own efforts that his Bechirah has been taken away. (See also MESHECH CHOCHMAH, beginning of Va'era.) (I. Alsheich)
2) DIGGING A PIT NEXT TO A NEIGHBOR'S PIT
OPINIONS: The Mishnah states that a person may not dig a Bor (pit) next to his neighbor's Bor unless he distances his own Bor at least three Tefachim from the wall of his neighbor's Bor.
The Rishonim provide different explanations for what types of Bor the Mishnah discusses, and what damage may be caused when a person digs a Bor next to his neighbor's Bor.
(a) TOSFOS writes that the Mishnah refers to a water cistern, a Bor that is used to hold water. A dry Bor, on the other hand, may be dug within three Tefachim of a neighboring Bor. A Bor that is used to hold water must be distanced because the moisture will damage the wall of the neighbor's Bor.
Tosfos, however, questions this explanation from the Gemara later (17b) which says that the neighbor can claim that "each thrust of your shovel weakens my land," which implies that it is the digging, and not the water, that damages the neighbor's land. Accordingly, the Mishnah is referring to all types of pits and not only to a water cistern.
Tosfos answers that the Gemara means that when one Bor is dug adjacent to another, the damage begins at the moment that one starts to dig. Accordingly, it is considered "Girei Dilei" (arrows that one shoots which cause damage). In such a case, Rebbi Yosi agrees (as the Gemara later explains) that the owner of the damaging object is obligated to distance his object. However, he would have to move only a minimal distance away, not a distance of three Tefachim, in order to avoid the damage that may be caused by the shovel. It is only because of the potential damage that will be caused by the water in the Bor that the minimum distance is set at three Tefachim.
The TOSFOS HA'ROSH (cited by the Shitah Mekubetzes) writes that only a small amount of damage will be caused by the strikes of the shovel, but the major damage will be caused by the water that the Bor will hold. Once the Chachamim required a person to keep his Bor at a distance because of the potential water damage, they also required him to move it because of the small damage that the shovel causes.
(b) The RAMBAN (cited by the Rashba, who himself agrees with Tosfos) maintains that the Mishnah's ruling applies equally to a dry Bor that does not hold water. The reason why one must distance such a Bor at least three Tefachim from his neighbor's Bor is that, as the Gemara says, each thrust of the shovel into the earth weakens the neighbor's land.
(c) The RA'AVAD (cited by the Shitah Mekubetzes to 19a) differentiates between a "Bor" and a "Shi'ach" or "Me'arah." (A Shi'ach is a narrow, elongated well, and a Me'arah is a cave-like structure that usually leads to a spring or water source.) When the Mishnah says that a person must not dig a Bor within three Tefachim of his neighbor's Bor, it refers even to a dry Bor, and the reason why he must distance his Bor from his neighbor's is because of the strikes of the shovel upon the earth. A Shi'ach or Me'arah, on the other hand, need to be dug three Tefachim away only when they will be used to hold water.
This difference is due to the fact that a Bor is relatively deep, and thus the digging itself weakens the neighbor's land. In contrast, a Shi'ach and Me'arah (and the other types of pits mentioned in the Mishnah) are not deep, and thus the act of digging them does not damage the neighbor's land. The land may be damaged, however, because of the water that they hold. (I. Alsheich)
3) THE NATURE OF THE REQUIREMENT TO DISTANCE A POTENTIALLY DAMAGING OBJECT
QUESTION: The Mishnah states that one may not dig a Bor (pit) next to his neighbor's Bor unless he distances his own Bor at least three Tefachim from the wall of his neighbor's Bor, so that the digging of his Bor will not damage his neighbor's Bor (see previous Insight). The Mishnah here and throughout the rest of the Perek lists other requirements of "Harchakah," distancing a source of potential damage from a neighbor's property.
The requirement to distance a potentially damaging object from someone else's property seems to fall within the category of the laws of the Arba'ah Avos Nezikin and the general laws of Nizkei Mamon, damages caused to someone else's property, the topic of Maseches Bava Kama. Why are these Mishnayos taught in Bava Basra and not in Bava Kama?
Moreover, the RAMBAM records these Halachos of "Harchakos" in Hilchos Shechenim, and not in Hilchos Nizkei Mamon. Why does the Rambam not include these Halachos in the laws of Nizkei Mamon?
ANSWER: The NESIVOS HA'MISHPAT (155:18) addresses this issue at length. He proposes that the laws of "Harchakos" of potentially damaging objects are not related to the laws of Nizkei Mamon, the obligation to avoid causing damage to someone else's property. Indeed, the Halachos of "Harchakos" are not consistent with the Halachos of Nizkei Mamon. According to the Halachos of Nizkei Mamon, if a person or his property (such as his animal) causes damage to someone else's property, he is obligated to pay for the damage (in part or in full, depending on the nature of the damage). However, the Gemara here (18b) teaches that when a person's bees eat his neighbor's mustard plant -- an occurrence which would seem to be identical to the classic case of Nezek of Shen, wherein an animal eats someone else's property -- the owner of the bees does not have to distance his bees from the mustard plant. Moreover, the Gemara implies that he is exempt from paying for the damage that the bees cause to the plant, for even when a person is obligated to distance an object from his neighbor's property, he is exempt from payment for any damage that was caused. (See SHULCHAN ARUCH CM 155:33; end of RAMBAN's Kuntrus Dina d'Garmi; YAD RAMAH to 25a. The RA'AVAD also infers from the Mishnah here that the owner of the object is exempt from paying for damages since the Mishnah phrases its Halachah as merely a prohibition to dig a Bor adjacent to a neighbor's Bor, and not as a monetary obligation. Had it been a monetary obligation, the Mishnah would have made a statement such as, "One who digs a Bor near his neighbor's Bor is Chayav.")
Furthermore, the Rishonim write that the obligation to distance a potentially damaging object from a neighbor's property is a Chiyuv d'Rabanan (RABEINU TAM in SEFER HA'YASHAR #616; MABIT in KIRYAS SEFER, Hilchos Shechenim 9), while the requirement to pay for damages of the Arba'ah Avos Nezikin is mid'Oraisa (as detailed in the first Perek of Bava Kama; with regard to the status of the prohibition to cause damage in the first place, see Insights to Bava Kama 2:3).
Why, though, do the general Halachos of Nezikin not include the requirement to distance a potentially damaging object from another person's property?
The Nesivos ha'Mishpat explains that the focus of this Perek is a potentially damaging object inside the owner's property. If a person would be held responsible to pay for damage caused by these objects, or he would be prohibited to use these objects because of the risk that they might damage a neighbor's property, then he would not be able to use them at all, even within his own domain. The Torah does not require a person to refrain from normal activities in his own domain out of fear that an object might cause damage elsewhere without leaving its present location. On the contrary, the potential victim should be obligated to protect himself, and the owner of the object should retain the right to use his own object in his own Chatzer. In contrast, the Halachos of the Arba'ah Avos Nezikin dictate that the owner of a Shor, for example, must guard his Shor in his own domain so that it will not leave his domain and cause damage elsewhere. The owner's obligation to guard a Shor inside his own domain, however, does not limit or restrict what he can do within his own property.
Further explanation of this distinction is found in SEFER TIFERES TORAH AL HA'SHAS (#33) by RABEINU HA'GAON RAV SHIMSHON PINCUS zt'l. He explains that the laws of Nezikin in Bava Kama relate to a situation in which the Mazik enters the domain of the Nizak or infringes on an area that the Nizak has the right to use. Damage that is caused in such a fashion falls into the category of "Nezikin." In contrast, the laws of "Harchakos" (in Bava Basra) do not involve a Mazik that enters the domain of the Nizak at all. Rather, these laws apply to a person who causes damage in his neighbor's property when he uses an object in his own domain. Since the damaging object did not leave the owner's domain, it is not subject to the laws of Nezikin discussed in Bava Kama. The discussion of the Gemara here is whether a person's rights of ownership over his own property include the right to use, in his own property, an object that will cause damage to a neighbor. The discussion involves the nature of the rights of ownership, or Kinyan, and it does not involve the laws of Nezikin. (I. Alsheich)