1) HASTENING A DEATH
QUESTION: The Gemara teaches that Rebbi Yishmael (beno Shel Rebbi Yochanan ben Berokah) and the Chachamim disagree in a case in which a person throws a Tinok from a roof and it becomes imbedded upon the horns of an ox before it reaches the ground. Rebbi Yishmael, who maintains that the payment of Kofer (which is paid when one's animal kills a person) is "Demei Mazik" (the value of the life of the Mazik), will rule that the owner of the ox is liable to pay for the life of the Tinok. The Chachamim, who maintain that Kofer is "Demei Nizak" (the value of the life of the victim), will rule that the owner of the ox is exempt. RASHI explains that according to the Chachamim, the owner of the ox is exempt from Kofer because the Tinok has no value; even if the ox would not have killed it, it would have died upon hitting the ground, and thus it was considered dead at the time that the ox gored it.
Why, though, should the owner of the ox be liable even according to Rebbi Yishmael? The Gemara earlier states that if a Tinok is thrown from a roof and it falls upon a sword held by a person, the Chachamim exempt the person holding the sword because he merely hastened the death of the Tinok; without him, the Tinok still would have died. The law is that whenever the owner of an ox would be exempt from Misah for killing in a certain way, an ox which kills in that manner is also exempt from Misah (44b). Rabah teaches (43a) that whenever the ox is exempt from Misah, the owner is exempt from Kofer. How can Rabah himself, who is the one who teaches the ruling here, state that according to Rebbi Yishmael the owner of the ox will be liable to pay Kofer even though the ox merely hastened the death of the Tinok, and it was not the primary cause of the death? (SHITAH MEKUBETZES)
ANSWERS:
(a) The SHITAH MEKUBETZES, TALMID HA'RASHBA, PNEI YEHOSHUA, and RASHASH explain that according to Rashi, Rabah must be expounding upon the opinion of Rebbi Yehudah ben Beseirah who argues with the Chachamim and maintains that one is Chayav Misah when one kills the Tinok while it is falling.
(b) RABEINU CHANANEL suggests an entirely different explanation for the words of Rabah, according to which the question does not begin. Rabeinu Chananel explains that it is not the Chachamim who exempt the owner of the ox from Kofer in the Gemara's case, but rather it is Rebbi Yishmael, who maintains that Kofer is "Demei Mazik," who exempts the owner of the ox from Kofer. He explains that according to Rebbi Yishmael, Kofer is necessary only when -- had the owner of the ox did what the ox did -- he would have been Chayav Misah. Since the owner of the ox would not have been Chayav Misah for killing the Tinok (as Rabah said in the previous statement, according to the Chachamim who argue with Rebbi Yehudah ben Beseirah), when his ox kills in such a manner he is exempt from Kofer. However, according to the Chachamim who maintain that Kofer is "Demei Nizak," Kofer is not related to the sin of the owner of the ox, but rather it is compensation for the Nizak who was killed (this follows the view of Rav Chisda in Makos (2b), and not Rav Papa who maintains that even if Kofer is "Demei Nizak" it is still an atonement for the sin). Therefore, according to the Chachamim, it will be necessary to pay Kofer even though the act that the ox did by killing the baby is not one that makes the owner Chayav Misah.
(According to this approach, it must be that Rabah, who rules (43a) that the owner does not pay Kofer when the ox is exempt from Misah, follows the opinion of Rebbi Yishmael that Kofer is a Kaparah, an atonement, and that Kofer is paid based on the value of the Mazik. See CHAZON ISH, Bava Kama 2:15.)
2) A "BI'AH" WITHOUT INTENTION
QUESTION: Rabah teaches that if a man falls from a roof onto his Yevamah, he is not Koneh her. RASHI explains that although Bi'as Shogeg is Koneh a Yevamah, since the man in this case had no intention for an act of Bi'ah at all, he is not Koneh her. Consequently, if one of the other brothers of the man does Ma'amar with the Yevamah, she becomes prohibited to the first brother since he was never Koneh her.
Why is this the only practical difference that Rashi can find -- that the Ma'amar of the second brother prohibits the Yevamah to the first brother? Rashi should give a more basic practical difference: since the first brother was not Koneh her, any other brother is permitted l'Chatchilah to be Koneh her with Yibum since she is not an Eshes Ish! If none of the other brothers want to perform Yibum, one must perform Chalitzah since the first brother was not Koneh her with his act, and it is not necessary for the first brother to give her a Get. (BIRKAS AVRAHAM)
ANSWER: The Gemara in Yevamos (96b) teaches that the Bi'ah of a nine year-old boy is considered like Ma'amar, even though he is a Katan and cannot have Kavanah for Yibum. Perhaps Rashi learns that the Bi'ah of a nine year-old is also without intention for Bi'ah, since a Katan is unable to have intention for Bi'ah. Nevertheless, the Bi'ah has the status of Ma'amar (which is like a Yibum mid'Rabanan). Rashi therefore learns that when a man falls off a roof onto his Yevamah, that Bi'ah without intention is also considered no less than Ma'amar. Consequently, it will not be permitted l'Chatchilah for any of the other brothers to perform Yibum with her since one brother has already done Ma'amar. Also, it will not suffice to send her away with Chalitzah since, after Ma'amar, a "Get Yivmin" is required, in addition to Chalitzah. Therefore, Rashi writes that the practical consequence of the man not being Koneh the Yevamah is that if another brother does Ma'amar (or if another brother gives her a Get, Chalitzah, or does Yibum; see Yevamos 50a), she becomes prohibited to the first brother.
Why does Rashi not say that the practical consequence is that she is not Chayav Kares (or Chayav to bring a Chatas) if she lives with someone else after the Yavam falls upon her? The answer is that the Gemara uses the words "Lo Kanah," implying that there is a practical consequence regarding the Kinyan of the Yevamah. If the only consequence was the status of the woman, the Gemara would have said that when the man falls upon her, "she does not become an Eshes Ish."

27b----------------------------------------27b

3) FOLLOWING A "ROV" FOR MONETARY MATTERS
QUESTION: The Gemara teaches that "Ein Holchin b'Mamon Achar ha'Rov" -- we do not follow the majority -- for monetary matters. Accordingly, if most people call a jug, "Kad," and a barrel, "Chavis," and a seller tells a purchaser that he is selling to him a "Chavis" and then delivers only a jug ("Kad"), the seller may claim that he calls a jug a "Chavis" even though most people do not call it such. Elsewhere (46b), the Gemara teaches that Rav and Shmuel disagree about whether we follow Rov in monetary matters. Shmuel teaches that we do not follow Rov for monetary matters. (See TOSFOS and Rishonim here who explain that even Rav agrees that in the case of the Gemara here we do not follow Rov.)
Why should we not follow Rov for monetary matters? The Torah teaches that we follow Rov with regard to all questions of Isur, and even with regard to questions of Dinei Nefashos (taking someone's life) (Chulin 11a, Sanhedrin 69a). Why should Dinei Mamonos be different? (TOSFOS, DH Ka Mashma Lan, and TOSFOS to Sanhedrin 3b, DH Dinei Mamonos)
ANSWERS:
(a) TOSFOS in Sanhedrin answers that the Rov which the Gemara here discusses is not as strong as the other instances of Rov which apply even in cases of Dinei Nefashos. If we follow the stronger type of Rov in order to execute a person, we certainly may take someone's money based on that Rov. The Rov of the Gemara here, however, is weaker, and it cannot be used to kill a person or take money. It can be used only to establish the presence or absence of an Isur.
Why, though, is this Rov weaker than a normal Rov?
The SHEV SHEMAITSA (4:6) cites the RAMBAN in Kidushin (50a) who writes that a Rov based on a natural phenomenon is stronger than a Rov based on the way a person chooses to act, because a person can choose to act like the minority. For example, the Gemara teaches that most women are not born sterile, that most oxen are not born as Tereifos, and that most women give birth after nine months and not after seven. All of these cases of Rov are part of the nature of the world and do not depend upon a person's choice. In contrast, the Rov that most people call a jug a "Kad," or that most people buy oxen for plowing and not for slaughter, can be superseded by a person's choice, when a person decides that he does want to call a jug a "Chavis" or to buy an ox in order to slaughter it. The Ramban writes that the Rabanan normally relied even on the weaker type of Rov with regard to Isurim (except under certain circumstances, such as when it is a question of Isur Eshes Ish).
The Shev Shemaitsa explains that this is what Tosfos here means as well. The only Rov that does not affect monetary matters is the weaker Rov, which depends on a person's choice. Such a Rov is also not taken into consideration with regard to Dinei Nefashos. (In 4:7, the Shev Shemaitsa points out that this answer of Tosfos does not seem fully consistent with the Gemara in Bava Basra (93a) which relates the opinion of "Ein Holchin b'Mamon Achar ha'Rov" to the fact that most animals give birth to live offspring and not to stillborns, which is a natural Rov.)
(b) TOSFOS here seems to maintain that even when we do rely on a Rov for Dinei Nefashos, we do not rely on it with regard to monetary matters, because with regard to monetary matters a Chezkas Mamon (of the person who is presently in possession of the money) cancels out the Rov of the person trying to take the money.
The Shev Shemaitsa (4:8) asks in the name of his brother why we do not apply the same logic to Dinei Nefashos, since the person being judged has a Chezkas ha'Guf that he is alive and thus deserves to continue in that state, which counters the Rov that says that he is Chayav Misah. (See the answer of the Shev Shemaitsa there.)
Perhaps the Chezkas ha'Guf that the person is alive cannot counter the Rov that says that he is Chayav Misah, because the judges do not decide directly whether he is to be killed or not. Rather, they decide whether or not he did an Aveirah (for which he is Chayav Misah). The fact that he is alive has no bearing on whether he did an Aveirah or not. After the judges determine, based on the Rov, that he committed an Aveirah, with the authority of Beis Din they rule that he is to be killed for committing that Aveirah. Even a Chezkas Mamon cannot negate the ruling of a Beis Din, as Tosfos himself proves from the fact that the Beis Din is able to take money from someone based on the ruling of most (a Rov) of the judges. In contrast to Dinei Nefashos, for monetary matters the Chezkas Mamon comes into account when the judges decide whether or not the person must pay, since the judges' decision centers on whether money should be paid or not (and not on whether a certain act was done or not); they are ruling on the question of "does this person owe money or not" and not on the question of "did this person commit a certain act or not." Therefore, the Chezkas Mamon must be taken into account at the time the judges make their decision, and thus it is able to override the Rov and cause the judges to decide in favor of the one who has the Chezkas Mamon.