פירוש על בבא קמא 18:18

The way [of the ox is] to proceed and cause damage. While the Braita is discussing the relative stringent and lenient aspects of the avos, the Braita does not mention some of the stringent characteristics mentioned in our Mishna. For example, the Braita does not mention that shor is alive, which is mentioned in our Mishna. Nor does it mention that shor has intent to damage, which is mentioned in the Gemara on 2b. Tosafot wants to know why these chumros were not mentioned in the Braita. The first stringency Tosafot addresses is that Shor is alive.
The reason the Braita does not mention that shor is alive which is not so of bor is because that is included in the chumro - stringency mentioned, and it is usual for shor to travel and damage.¹It seems from Tosafot that the traveling and damaging is a function of being alive. Although that is definitely true, it does present a problem in the understanding of our Braita. Our Mishna describes aish as “it usually travels and damages” even though it is not alive. We are compelled to say that Tosafot is referring to the reality that in the case of shor it does travel and damage because it is alive, although there certainly are situations where an av travels and damages even though it is not alive.
And that shor has intent to damage cannot be mentioned in contrast to bor which is not alive and inherently is incapable of intent.²Tosafot seems to hold that we cannot say that av A has a chumro over av B when av B is inherently incapable of that chumro, such as in the case before us. We cannot say that keren has the chumro of intent to harm as opposed to bor that does not when bor is inherently incapable of having that chumro since it is not alive. This is a bit problematic. Later the Gemara says that shor has a chumro that bor does not have. Shor is liable for trampling on a plowed field while bor is not. In that case bor is inherently incapable of trampling because it does not move and yet the Gemara presents it as a chumro. Some commentators explain that Tosafot does not mean that we cannot make a comparison when one of the avos is incapable of a particular function, such as the bor’s incapability of moving. We certainly can refer to this as a leniency of bor. Tosafot only said that this Braita cannot mention that shor has intent to harm as opposed to bor which does not have intent since it is not alive, because the Braita already alluded to the fact that shor is alive as opposed to bor, when it said that shor travels and damages and bor does not. Since the Braita already alluded to the underlying reason that bor does not have intent it cannot again present its lack of intent as a leniency.

Which is not true regarding the pit. The Braita says that when a person is killed in a bor, the bor owner does not pay kofer. And the same is true of aish, as the Braita soon teaches us when comparing shor to aish, that shor pays the kofer which is not so of aish.
It is clear from the Braita that both bor and aish do not pay kofer. What is not clear is the source of this ruling.¹Rashi in ד"ה מה שאין כן בבור says that the source for the exemption of bor is in Shemot 21, 33 “shor” and not a person, that teaches us that bor is not liable for the death of a person. Rashi on 10a ד"ה מה שאין כן באש explains why aish is exempt form the payment of kofer. A person may be killed by an aish if he did not run away from the fire. In that case the one who kindled the fire is exempt because the victim should have run away. If the victim was tied and could not run away the perpetrator is also exempt from payment of kofer, because of the rule - a lesser punishment is canceled by a greater punishment. Since the perpetrator will be liable for capital punishment, that cancels the lesser punishment of kofer. Tosafot does not even mention Rashi’s sources for these two rulings. Obviously, he does not accept them. Why not? Aish that may be exempt because of a smaller punishment being canceled by a greater punishment, assumes that starting a fire is equivalent to shooting an arrow and it is as if a person killed by his own power, not by allowing his property to damage others. It is only when a person kills by himself that he is liable for capital punishment. This explanation of aish is actually the subject of a dispute later in the Gemara between R’ Yochanan and Resh Lokish. Tosafot feels that it is insufficient to quote a source that is only correct according to one opinion in the Gemara. In addition, it is clear later in the Gemara that even according to R’ Yochanan there are instances when aish is considered one’s property that is damaging and not as if he had shot an arrow. Those cases are not covered by Rashi’s explanation. Tosafot feels that there should be a source for all types of aish. As far as the source that Rashi quoted for bor, it is possible that Tosafot agrees with Rashi that this is a possible source. We will see later in Tosafot that Tosafot himself questions why we need the teaching “shor” and not a person, when we have the source that Tosafot furnishes. Although Tosafot finds an answer to this question, he may agree that the source Rashi quoted is in fact accurate. The reason that Tosafot does not use Rashi’s source is because it only answers bor, it does not answer aish. Since Tosafot had to find a source for aish that will at once answer bor as well, he does not mention Rashi’s source for the exemption of bor from kofer.
And if you ask: And we should learn from shor²Tosafot means by the method of בנין אב- a general principle. When the Torah teaches us a law, such as the payment of kofer when a shor kills with its keren, it is logical to learn from keren that when one kills a person by one of the other avos that he is also liable for kofer. This system of learning the rules of one av from another is subject to refutation as Tosafot will soon show us. See Tosafot 2a ד"ה לא הרי השור כהרי המבעה note 1, for further clarification. and they, bor and aish, should be liable for kofer? And even though it can be said as a refutation of this comparison to shor, that shor is alive and that is why it has a chumro to pay kofer while bor and aish are not alive, and that is why they do not have the chumro of paying kofer, ultimately, this refutation cannot be used. For the Gemara concludes later in perek Kaitzad (26a) that there is liability for kofer when a person is killed by regel. We see that we learn that regel is liable from keren, and we do not refute the derivation by arguing how can you compare regel to keren? Keren should be liable because it has intent to damage which regel does not and it also has another chumro that it is liable in a public domain where regel is not liable. We see that when learning from keren that another av should be liable for kofer we do not present the usual refutations that would disallow the derivation.³Tosafot seems to be saying that we do in fact see that the derivation from keren is not subject to refutation. This is truly perplexing; why should it not be subject to refutation? Actually Tosafot later 26a asks this question and leaves it unanswered. Tosafot Rabbeinu Peretz says that in the verse dealing with kofer we have the words והועד בבעליו, these words teach us that in addition to keren which is first a tam and then becomes a muad, all avos that are initially muad are also subject to the kofer fine, this could of course include bor and aish if we do not find a verse to teach us that this derivation is not to be applied to bor and aish.
We must agree that shor could be used as a source to teach us that all other avos are liable to pay kofer when they kill a person. We must now have a verse that teaches us that we should not learn from shor that all avos should be liable for kofer payment.
And we can answer: That aish and bor are exempt from kofer because we expound the verse in Shemot 21, 30, “If he shall place kofer on him”, on him, refers to the shor and we understand that the liability for kofer is exclusively on him, the shor, and not on the bor. The same applies to aish- on him, the shor, and not on the aish, just as the Gemara expounds this verse at the conclusion of Kaitzad (ibid.) on him, the shor; there is liability for kofer and not on the person who kills.⁴But why does this exclusion not apply to shain and regel as well? We should say that the very same verse that excludes Aish and bor from kofer also excludes shain and regel as well. See אוצר התוספות note 1681 who explains that the exclusion is about the word שור, and that word includes shain and regel which are also primary damager of שור, but excludes bor and aish which are not related to שור.
We now see that there is a specific source - on him, and not on the bor - to teach us that bor is not liable for kofer when a person is killed by bor. In the verse dealing with bor, the Torah writes “and an ox or a donkey will fall into it”. The Gemara expounds the word “an ox” to exclude a person who falls into a bor. (See note 1) One is only liable if an animal falls into his pit and not when a person falls into his pit.
And if you ask: the teaching shor and not a person, which is written by bor to exclude a person who fell into the bor, why is it necessary? It can be derived from the verse written in regard to kofer, on him, the shor there is an obligation to pay kofer and not on a bor that kills.
Tosafot question assumes that “an ox and not a bor” excludes the bor owner from the payment of kofer. In order to answer Tosafot question we must depart from that assumption.
And we can answer: The verse that teaches us that the victim of bor must be a shor and not a person is needed to exempt the bor owner when a Canaanite slave falls into the bor or when a gentile who was owned by a Jew⁵A Canaanite slave is completely owned by his master. His very body is the property of his master and he has a special status. He is obligated to observe the mitzvos that a woman must observe. If a Gentile does not wish to partially convert to the status of a Canaanite slave one may not keep him as a slave. One can however have a long term contract on his labor. This is what is meant by a gentile who belongs to a Jew. When he is killed the Jew loses the value of his labor contract with the gentile. He must be compensated. However, when the cause of the gentile’s death is a bor, the bor owner is exempt. falls into the bor. In either of these cases there is no kofer payment and thus there is no need to exclude the bor from payment of kofer. The verse is needed to exempt the bor from paying for the value of the slave⁶When a slave is killed by keren, there is a special payment of thirty sh’kolim that one must pay. Most commentators hold that the same rules that apply to kofer apply to the thirty sh’kolim of a slave. Those avos that are excluded from paying kofer such as a bor or aish need not pay the thirty sh’kolim for the slave. The payment that Tosafot is referring to is the actual value of a slave. One may be exempt from the kofer payment but still be liable for the loss the slave owner incurs by the death of his slave. For this we require a special exclusion, “shor” and not a person. or the Gentile owned by a Jew. That could not be derived from the verse “on him” and not on the bor, because that verse is speaking exclusively about kofer and not the payment for the value of the slave.