1) PARTNERS IN DAMAGE: WHO IS RESPONSIBLE?
QUESTION: The Mishnah (52a) states that when an ox falls frontward into a Bor as a result of being frightened by a noise made by someone digging in the Bor, the owner of the Bor is liable for the damage done to the ox. However, when the ox falls backwards into the Bor as a result of the noise, the owner is exempt.
Shmuel (53a) states that the owner of the Bor is liable both when an ox falls forwards and when it falls backwards. When the Mishnah says that the owner is exempt when the ox falls backwards, it refers to a case in which the ox trips on the Bor and falls outside the Bor (on the ground, not inside the Bor).
The Gemara later cites a Beraisa which records a dispute between the Tana Kama and Rebbi Nasan. When one ox pushes another into a Bor, according to the Tana Kama only the owner of the ox that pushed is liable. According to Rebbi Nasan, the owner of the ox and the owner of the Bor are liable, and each pay for half of the damage.
Rava comments that the law in another case depends on the dispute between the Tana Kama and Rebbi Nasan. The Tana Kama and Rebbi Nasan will disagree about the law in a case in which a person places a stone at the edge of a Bor and an ox comes and trips on it and falls into the Bor. RASHI (DH Banu) explains that according to the Tana Kama, the owner of the stone is liable for all of the damage because he started the damage (see also Rashi DH Mai). According to Rebbi Nasan, the owner of the stone and the owner of the Bor must pay equally.
What is the difference between Rava's case and Shmuel's explanation of the Mishnah? In Rava's case, the fact that the ox slipped on the stone is that makes the owner of the stone liable to pay at least half the damages. Why, then, when the ox trips on the Bor and falls outside the Bor does everyone agree that the owner of the Bor is exempt entirely? Although it was the ground of the Bor that actually inflicted the damage in Rava's case and the stone merely caused the ox to fall, nevertheless the owner of the stone must pay. Why does the owner of the Bor not have to pay in the case of the Mishnah, when it was the Bor that caused the ox to fall on the ground?
ANSWERS:
(a) The BA'AL HA'ME'OR (23b of the pages of the Rif) answers that when the Mishnah states that if the ox falls backwards the owner of the Bor is exempt, it means only that he is exempt from paying Nezek Shalem (full damages). He in fact is liable to pay Chatzi Nezek (half of the damage).
The Ba'al ha'Me'or writes that the Mishnah follows the second version of Rava in the Gemara. In the second version, Rebbi Nasan maintains that when an ox pushes another ox into a Bor, it is considered as though the ox did half of the damage and the Bor did half of the damage (and not that each one is considered to have done all of the damage).
Similarly, according to Shmuel, in the Mishnah's case of an ox which tripped on the Bor and fell on the ground next to the Bor, it is considered as though the Bor did half of the damage and the ground did half of the damage. The ground has no owner from whom the damagee may claim half of the damages. Therefore, in this case Rebbi Nasan agrees that the owner of the Bor pays only half. This supports the Gemara's conclusion that the Mishnah follows the opinion of Rebbi Nasan.
(b) The RAMBAN (in Milchamos) answers that the question is based on a faulty premise. In the case of the Mishnah, the ox fell because of the noise made by the person digging in the Bor, and not because of the Bor itself. If not for the digger's frightening noise, the ox would have suffered no damage.
Moreover, not only was the Bor not the initial cause of the damage but it also did not inflict the damage; the blow came from the ground of the public domain which is ownerless. Therefore, the Bor neither caused the start of the damage nor inflicted the damage. It therefore is understandable why the owner of the Bor is exempt entirely. In contrast, in Rava's case the stone at the edge of the Bor started the actual damage, and thus everyone agrees that its owner is liable for at least part of the payment. (See also PNEI YEHOSHUA.) (D. Bloom)

53b----------------------------------------53b

2) THE TEACHING OF "AN OX BUT NOT A MAN"
QUESTION: Rava presents several laws concerning an ox and a man who pushed something into a Bor. One of the laws is that if they pushed an ox of Pesulei ha'Mukdashin (a sanctified ox that became disqualified from being offered as a Korban), the man and the owner of the ox are liable for the damage they did, while the owner of the Bor is exempt. The Gemara says that this is because the verse (Shemos 21:34) states that when something falls into a Bor and is killed there, "the carcass shall be his (the owner's, as partial payment)." This verse excludes an ox of Pesulei ha'Mukdashin which can never belong to the owner of the Bor. Although it has been redeemed, it still must be buried and cannot be sold because it is forbidden from benefit (see Avodah Zarah 29b). Since the carcass cannot belong to the owner of the Bor, he is exempt from paying for the animal.
The Mishnah (52a) states that if an ox laden with vessels falls into a Bor and the vessels break, the owner of the Bor is liable for the damage done to the animal and exempt for the damage done to the vessels. The Gemara (53b) explains that the Mishnah follows the view of the Rabanan who derive from the verse "and an ox or donkey falls in it" (Shemos 21:33) that the owner of a Bor is liable only for damages caused to "an ox" and not to a man, and only for damages caused to a "donkey" and not to vessels.
According to Rava, why is it necessary for the verse to teach "'an ox' but not a man"? There is another reason for why the owner of the Bor is exempt from damages done to a person: just as one is exempt in the case of the death of an ox of Pesulei ha'Mukdashin because one is forbidden to derive benefit from it, one should be exempt in the case of the death of a man because one is forbidden to derive benefit from a human corpse.
ANSWERS:
(a) TOSFOS in Zevachim (71b, DH vib'Tereifah) answers that the teaching, "'an ox' but not a man," is necessary for the following reason. The verse, "the carcass shall be his," does not teach that in the case of a man who fell into a Bor and died, the owner of the Bor is exempt from payment because of the prohibition against deriving benefit from a human corpse. Since one is permitted to benefit from certain parts of a human body according to Torah law (such as the skin), one would not have known that the verse intends to exempt the owner of the Bor from liability when a man falls into the Bor and dies.
(The Gemara in Chulin (122a) states that benefiting from the skin of a corpse is prohibited only mid'Rabanan. The Rabanan enacted this decree in order to prevent a person from making a bedspread out of the skin of his father or mother. See RAMBAN to Chulin there, and See Insights there.)
However, TOSFOS earlier in Bava Kama (10a, DH sheha'Shor) rejects this answer. The fact that one is permitted to derive benefit from the skin of a human corpse does not mean that a human corpse is included in the verse, "the carcass shall be his," because one is also permitted to benefit from the hair of an ox of Pesulei ha'Mukdashin (see Bechoros 25a) and nevertheless it is excluded from the verse. Tosfos explains that as long as the primary part of the body is forbidden from benefit, the verse would not say that "the carcass shall be his" and refer to a small part of the body from which one may derive benefit.
(b) TOSFOS (10a) gives a different answer. The verse refers only to the carcass of an ox and not to the corpse of a human. Tosfos proves this from the Gemara here which asks, how does one know that this verse, "the carcass shall be his," exempts the owner of the Bor when the ox of Pesulei ha'Mukdashin falls in because he cannot own the body, and that only when the owner of the Bor can own the body must he pay? This same wording ("the carcass shall be his") is used in the case of a Shor which damages (Shemos 21:36). The Gemara derives from that verse that the owner of the ox must pay for damages and the damaged party retains the carcass! The Gemara asks that perhaps the opposite is true: the owner of the Bor must pay for the damages, while in the case of the Shor the owner is exempt.
Tosfos asks, how could the Gemara have thought that the verse about Shor teaches that the body of a person killed by one's Shor also belongs to the owner? The verse (Shemos 21:30) explicitly discusses cases in which the Shor killed a person, and thus the Torah obviously cannot mean that the body belongs to the owner of the Shor. Tosfos concludes that the verse of Shor refers only to a case in which the Shor killed an animal. Accordingly, it is clear why the teaching of "'an ox' but not a man" is necessary. This law cannot be derived from "the carcass shall be his" since the Gemara clearly understands that the verse does not refer to a case of a man who fell into a Bor. (D. Bloom)