1) THE "SHECHITAH" OF A "BEN PEKU'AH"
QUESTION: The Gemara discusses a case in which the fetus of a pregnant animal of Chulin was sanctified to be a Korban Shelamim (according to the opinion that maintains that a fetus can become Kadosh with Kedushas ha'Guf). Abaye asks Rav Yosef whether the animal may be slaughtered outside of the Azarah of the Beis ha'Mikdash, or whether that would constitute a transgression of the Isur of Shechutei Chutz, slaughtering a sanctified animal outside of the Beis ha'Mikdash, since the fetus inside the animal is Kadosh.
According to Torah law, when an animal is slaughtered and a live calf ("Ben Peku'ah") is found inside of it, the calf does not need Shechitah in order to be permitted to be eaten. Since the mother was slaughtered, the Ben Peku'ah does not need Shechitah.
If the Ben Peku'ah does not need Shechitah, then what is Abaye's question? No Shechitah outside of the Azarah was done to the fetus!
ANSWER: The Acharonim discuss the nature of the Heter of Ben Peku'ah. Is the Ben Peku'ah permitted to eat without its own Shechitah because the slaughter of the mother exempts the calf from Shechitah, or is it permitted because when the mother is slaughtered, it is considered as though the calf was also slaughtered?
RAV SHIMON SHKOP (in SHA'AREI YOSHER 2:22) proves from the Gemara here that it must be that the Shechitah of the mother cow is considered to have been done to the fetus, because, otherwise -- if the fetus needs no Shechitah at all -- there would be no reason to consider this a case of slaughtering a sanctified animal outside of the Beis ha'Mikdash.
2) "MAYIM SHE'UVIN L'FI CHESHBON"
OPINIONS: The Mishnah states that Mayim She'uvin (drawn water) invalidates a Mikvah "l'Fi Cheshbon" ("according to calculation"). The Gemara asks who the Tana of the Mishnah is, and suggests that it is the opinion of Rebbi Eliezer ben Yakov. Rebbi Eliezer ben Yakov maintains that when there are 21 Se'ah in a Mikvah, one may add another 19 Se'ah of Mayim She'uvin and make it a valid Mikvah through the process of Hamshachah (pouring the Mayim She'uvin into a small ditch that leads to the Mikvah).
In what way does the Mishnah express the opinion of Rebbi Eliezer ben Yakov?
(a) RASHI (12b, DH Michlal and DH Ela) explains that the Mishnah is expressing the view of Rebbi Eliezer ben Yakov, because the Mishnah says that the Mayim She'uvin invalidates a Mikvah only "l'Fi Cheshbon," which means that the Mayim She'uvin invalidates the Mikvah only when it constitutes the majority of the water in the Mikvah. It is Rebbi Eliezer ben Yakov who maintains that only 19 Se'ah (a minority of the Mikvah) of Mayim She'uvin may be added.
The Gemara asks that this implies that the Chachamim, who are stringent and argue with Rebbi Eliezer ben Yakov, maintain that such a Mikvah (with 19 Se'ah of Mayim She'uvin) is invalid. This is problematic, however, because Ravin says that one may make an entire Mikvah in this manner (through Hamshachah)! If neither the Chachamim nor Rebbi Eliezer ben Yakov maintain that the entire Mikvah may be made in this manner, then how can Ravin say that such a Mikvah is valid? The Gemara therefore rejects the suggestion that the Tana of the Mishnah is Rebbi Eliezer ben Yakov, and it cites Rav Papa instead, who quotes a Tosefta in which the Tana Kama says that it does not matter how many vessels are used to pour the Mayim She'uvin into the Mikvah; pouring the contents of even four or five vessels, which together contain three Lugim of Mayim She'uvin, into a Mikvah cause it to become Pasul. Yosef ben Choni says that the Mikvah is valid only when the three Lugim are poured in three separate acts of pouring, each containing one Log. The Mishnah is expressing the view of Yosef ben Choni; when it says "l'Fi Cheshbon" it means that there must be a pouring of Mayim She'uvin "according to a Cheshbon," a certain amount, in order to invalidate the Mikvah. According to Rav Papa's answer, Ravin's statement is expressing the view of the Tana Kama of the Tosefta who indeed is more lenient than Rebbi Eliezer ben Yakov.
(b) TOSFOS (12a, DH v'Ein) quotes RABEINU SHMUEL MI'LUNIL who rejects Rashi's explanation of the Gemara for a number of reasons and understands the Gemara differently. He explains that when Ravin says that one may do Hamshachah with the entire Mikvah in this manner, he means that 40 Se'ah of water that gathered in an area through Hamshachah can be considered a valid Mikvah if 40 Se'ah of valid Mikvah water falls on it in a valid manner. Accordingly, no one actually argues with Ravin's statement. Rebbi Eliezer ben Yakov may agree with Ravin, because Rebbi Eliezer's ruling was said only with regard to making Mayim She'uvin part of the 40 Se'ah, and not making a lot of Mayim She'uvin into a Mikvah.
However, if this is the meaning of the Gemara, then the Gemara's question on Ravin is difficult to understand. The Gemara asks that Ravin's statement is in accordance with neither Rebbi Eliezer nor the Chachamim. According to Rabeinu Shmuel, why does the Gemara insist that Ravin's opinion is not consistent with the opinions of Rebbi Eliezer and the Chachamim? They are discussing two different cases!
The RI explains the Gemara's question in the same manner as Rabeinu Shmuel. When the Mishnah states that Mayim She'uvin invalidates a Mikvah "l'Fi Cheshbon," it implies that the Mishnah is discussing an amount of Mayim She'uvin that will make the Mikvah irreversibly Pasul. However, Rebbi Eliezer ben Yakov says that only when there are originally 21 Se'ah of Mikvah water will the Mayim She'uvin be considered part of the Mikvah. If there is less than this amount, the Mikvah will be irreversibly Pasul. This is not consistent with the opinion of Ravin, because Ravin would say in such a case that one could have this water run into another area, and he could arrange afterwards to have 40 Se'ah of valid Mikvah water fall there. According to Ravin, the location of the Mikvah is adjustable. The Chachamim, who argue with Rebbi Eliezer ben Yakov and maintain that the presence of 21 Se'ah of valid Mikvah water does not validate 19 Se'ah of Mayim She'uvin even through Hamshachah, are more stringent than Rebbi Eliezer ben Yakov. They presumably agree that this water cannot be fixed by Hamshachah and forty Se'ah. This is why the Gemara says that Ravin's statement is consistent with neither Rebbi Eliezer ben Yakov nor the Chachamim. (As Rabeinu Shmuel says, if not for the wording of the Mishnah, one could have said that the Tana'im agree with Ravin's ruling.) (Y. MONTROSE)
3) DID TOSFOS FORGET THE GEMARA?
QUESTION: The Gemara says that according to the Tana of the Mishnah here (12a), the verse, "v'Nasan Alav Mayim Chayim El Keli" -- "and he will put on it live water in the vessel" (Bamidbar 19:17), teaches that after the ashes of the Parah Adumah are placed on the water, the water should be put back onto the ashes; that is, the water and ashes should be mixed up as if the water has been placed on top of the ashes.
The Gemara here poses a difficulty to the words of TOSFOS in Yoma (43b, DH ha'Kol Kesheirin). Tosfos there quotes RASHI (DH l'Kadesh) as saying that the water is poured on the ashes of the Parah Adumah in order that the mixture should acquire the status of Mei Chatas. Tosfos says that the Mishnah in Maseches Parah states numerous times that the process is done in the opposite manner -- by placing the ashes on top of the water that has already been poured into the vessel. Tosfos continues to ask that those Mishnayos seem to contradict the verse that says that one must take the ashes and "put on it live water," which seems to support the words of Rashi. Tosfos answers that it is possible to say that the verse "v'Nasan Alav" does not mean "on top of [the ashes]," but rather "because of the ashes." Tosfos concludes that it is clear from the end of the verse that the water must be placed in the vessel first, as it says, "live water in the vessel."
The Acharonim (MAHARSHA to Sotah 16b, BIRKAS HA'ZEVACH, TOSFOS YOM TOV, and others) are perplexed by the words of Tosfos. The Gemara here explicitly addresses the question of Tosfos and explains that "v'Nasan Alav" means that after the ashes are placed onto the water, the water and ashes should be mixed together. Why does Tosfos ask his question if the Gemara itself addresses it?
Moreover, why does Tosfos give an entirely different answer to the Gemara's question? (The Tosfos Yom Tov is so perplexed by the words of Tosfos that he suggests that it seems that Tosfos forgot the Gemara here.) How are we to understand the words of Tosfos?
(a) The TEMURAS TODAH is perplexed with the question of all of the Acharonim. Tosfos quotes Rashi as saying that the water is placed on the ashes, while the Mishnayos in Parah say that the ashes are placed on the water. Why does Tosfos not quote the explicit argument in the Gemara here about which one is placed in the vessel first? Why are the Acharonim not bothered by that question? Why are they not bothered that Rashi's explanation is unlike the view of the Tana Kama in the Gemara, who says that putting the water on the ashes invalidates the Mei Chatas?
The Maharsha indeed asks that Tosfos should have answered that Rashi follows the view of Rebbi Shimon here, who says that placing the water on the ashes does not invalidate the Mei Chatas. However, this answer is also problematic, because Rashi in Yoma (DH v'Rabanan) states explicitly that one should put the ashes on the water, a clear indication that he follows the view of the Tana Kama. How, then, can Tosfos (according to the Maharsha) claim that Rashi follows the view of Rebbi Shimon?
The Temuras Todah therefore asserts that Rashi and Tosfos are discussing an entirely different subject altogether. When Rashi (DH l'Kadesh) states, "... to put water on the ashes in the Kli Shares," he does not mean that this is the order of the preparation of the Mei Chatas, and that one must first put in the ashes and then the water. Rather, he means that both the water and the ashes must be placed in the vessel "Lishmah" -- with intention that they will be used as Mei Chatas (see RAMBAM, Hilchos Parah Adumah 9:1-2). Tosfos questions this requirement, because he understands from the Mishnayos in Parah that while the placing of the ashes on the water needs intent, the placing of the water in the vessel does not need intent. Tosfos then states that one should not think that the verse of "v'Nasan Alav" supports the view of Rashi and means that the water must be placed "Lishmah," because the verse means merely that the water is placed "Bishvilo" -- "because of" the ashes, which indeed must be placed "Lishmah."
There seems to be one difficulty with the Temuras Todah's answer. The words of Rashi that he is explaining (DH l'Kadesh), "... to put water on the ashes in the Kli Shares," do not seem to tolerate his explanation at all. Perhaps the Temuras Todah had a slightly different text of Rashi.
(b) The RISHON L'TZIYON (on Mishnayos) says that there is a mistake in the text of Rashi. He asserts that the words of Rashi should read, "to place on the water ashes," or "to place ashes on the water," and not "to pour water on the ashes." He adds that this mistake led a student to copy Rashi's words into Tosfos. (See NIMUKEI HA'GRIV and the TIFERES YISRAEL for other possible answers.) (Y. MONTROSE)
4) THE EXTENT OF A "BEIS HA'PERAS"
QUESTION: The Gemara asks how far the boundaries of a Beis ha'Peras extend, according to the Rabanan.
What is the Gemara's question? The Mishnah itself in Ohalos (17:1) explicitly states that the limit of a Beis ha'Peras is 100 Amos, exactly as the Gemara here eventually concludes based on a Beraisa!
ANSWER: The RASH in Ohalos writes that there are two types of Beis ha'Peras. The first type is a field in which the location of the grave was known before the field was plowed. The second type is a field with a grave that was plowed, and the location of the grave was not known. The Mishnah in Ohalos is discussing the first type of Beis ha'Peras, where the location of the grave was known, and it is saying that the Beis ha'Peras extends 100 Amos from the location of the grave. The Gemara here, in contrast, is asking what the limits of a Beis ha'Peras are in a case the location of the grave was not known. It answers that the Beis ha'Peras extends 100 Amos from the boundaries of the field.
(The Rash, however, does not accept this explanation. If the Gemara is discussing a case in which the location of the grave was not known, then why does the Beis ha'Peras extend a distance of 100 Amos from each end of the field? There is a Sfek Sfeika with regard to the location of the bones in all of the surrounding fields, and thus they should not have the status of a Beis ha'Peras. The first doubt is that perhaps the grave was at a side of the field that is farther than 100 Amos from the neighboring field on the opposite side (and thus no bone ever went as far as that neighboring field). The second doubt is that even if the grave was at the side closer to this neighboring field, perhaps the plow did not drag any bones into the neighboring field at all.)