1) THE NEED FOR TWO SOURCES TO TEACH THAT BOTH "NEVEILAH" AND "TEREIFAH" APPLY TO "CHELEV"
QUESTION: Rava learns from the apparently extra verse, "v'Chelev Neveilah v'Chelev Tereifah... v'Achol Lo Sochluhu" -- "the Chelev of a Neveilah and the Chelev of a Tereifah... you shall not eat it" (Vayikra 7:24), that the Torah applies both the Isur of Neveilah and the Isur of Tereifah to Chelev. If not for this verse, one would have thought that neither of these Isurim applies to Chelev, because of the principle of "Ein Isur Chal Al Isur." Since the item is already prohibited because of the Isur of Chelev, the Isur of Neveilah and the Isur of Tereifah cannot take effect. The Torah here teaches an exception to the general rule.
The Gemara asks why the Torah needs to state that both Isurim, Neveilah and Tereifah, apply to Chelev. It would have sufficed to teach that one of them applies, and one would have been learned from the other. The Gemara answers that one would not have been able to derive one from the other. Had the Torah taught that the Isur of Neveilah applies to Chelev, one would have known only that Neveilah applies to Chelev, but not that the Isur of Tereifah applies to Chelev. One would have said that since Neveilah causes people to become Tamei, it is a very severe prohibition, and thus it also applies to Chelev. The Isur of Tereifah, in contrast, would not apply to Chelev because of the general rule of "Ein Isur Chal Al Isur."
On the other hand, had the Torah taught only that the Isur of Tereifah applies to Chelev, one would not have been able to learn Neveilah from Tereifah, because the Isur of Tereifah is more severe since it applies even when the animal is alive. Thus, it is a strong enough prohibition to apply to Chelev. The Isur of Neveilah, in contrast, applies only after the animal dies, and thus the general rule of "Ein Isur Chal Al Isur" would prevent it from applying to Chelev. This is why the Torah needs to mention both Neveilah and Tereifah.
TOSFOS (DH v'Iy) asks that there seems to be a contradiction between the logic of the Gemara here and the logic of the Gemara in Chulin (37b). The logic which the Gemara here uses to show that Tereifah is a stronger Isur is that the Isur applies even when the animal is alive. However, the Gemara in Chulin gives the same feature of the Isur of Tereifah as a reason for why it is a weaker prohibition! The Gemara there attempts to make a Kal va'Chomer to derive Neveilah from Tereifah: if the Isur of Tereifah, which takes effect when the animal is alive, applies to Chelev, then certainly the Isur of Neveilah, which takes effect after the animal's death, should also apply to Chelev. This is the exact opposite of the logic of the Gemara here. How are these two Gemaras to be reconciled?
(a) TOSFOS here refers to his explanation in Chulin (37b, DH u'Mah me'Chayim). There, Tosfos quotes RABEINU TAM who explains that the Gemara in Chulin is questioning its original assumption that a Mesukenes (an animal with physiological symptoms of impending death, as discussed in the Mishnah there) is forbidden and is considered a Tereifah. The Gemara asks that if the Isur to eat an animal that is a Tereifah, which does not cause Tum'ah while it is alive, takes effect on Chelev, then certainly the Isur of Neveilah, which does cause Tum'ah, takes effect on Chelev. At this stage, the Gemara assumes that every Neveilah is first a Mesukenes before it dies, and thus the animal is forbidden as Neveilah even while it is alive, because it certainly will become a real Neveilah. This is why the Gemara cannot refute its Kal va'Chomer by saying that the Isur of Tereifah is unique because it applies even when the animal is alive; the Isur of Neveilah also applies when the animal is alive, because of its status as a Mesukenes! The Gemara here in Zevachim, however, knows that a Mesukenes is not forbidden. Consequently, the Isur of Neveilah takes effect only when the animal dies, and thus the Isur of Tereifah, which takes effect while the animal is still alive, is considered a stronger prohibition.
(b) The MAHARAM in Chulin has a different text of Tosfos here in Zevachim. Instead of the words, "v'Sham Pirashti" -- "and there (in Chulin) I explained it," as our text of Tosfos reads, the Maharam's text of Tosfos reads, "v'Sham Piresh Rashi" -- "and there Rashi explained it."
What is Rashi's answer to this question? The Maharam explains, based on Rashi in Chulin (DH u'Mah me'Chayim, DH Michlal), that the Gemara's conclusion is that the Isur of Tereifah indeed is more stringent than the Isur of Neveilah. The Isur of Tereifah is not due to the fact that the animal is going to die and become a Neveilah. Rather, the Torah forbids eating an animal which is missing vital parts. Therefore, the Gemara here in Zevachim says that if the Torah would have taught only that the Isur of Tereifah takes effect on Chelev, one would not have known that the Isur of Neveilah also applies to Chelev, since Neveilah takes effect only after the animal dies. The Gemara in Chulin, however, originally assumed that the Isur of Tereifah is due to the fact that the animal is about to become a Neveilah. If that is the reasoning behind the prohibition, then it makes sense to say that Neveilah is the stronger prohibition, since a Tereifah is forbidden only because of Neveilah. This also seems to be the opinion of the BIRKAS HA'ZEVACH in his comments to Tosfos here. (Y. MONTROSE)
2) WHEN DOES AN "EGLAH ARUFAH" BECOME FORBIDDEN FROM BENEFIT?
QUESTION: The Gemara teaches that an Eglah Arufah becomes forbidden from benefit once it descends to Nachal Eisan, the place where its beheading takes place. In Kerisus (24b), this opinion is expressed by Rav Hamnuna. Rava there argues that it becomes forbidden from benefit only after it is beheaded. The RAMBAM (Hilchos Rotze'ach 10:6) rules like the Gemara here (and the opinion of Rav Hamnuna) and writes that the Eglah Arufah's descent to Nachal Eisan forbids it from benefit.
The RASHBA (Teshuvos 5:16) was asked that the Rambam apparently contradicts himself. The Rambam, in the same chapter (Hilchos Rotze'ach 10:8), rules that if the killer was found before the calf was beheaded, then the calf may return to graze with its herd, which means that it is permitted to benefit from the calf. If the Rambam rules that the Eglah Arufah becomes Asur b'Hana'ah upon its descent to Nachal Eisan (even before it is beheaded), then it should remain Asur even if the killer is found! (The Rashba responds that he, too, was troubled by this contradiction, and after much effort he was unable to find a resolution.)
Is there any way to reconcile the words of the Rambam? (See also Insights to Kerisus 25:1.)
The RASHBA (Teshuvos 5:16) was asked that the Rambam apparently contradicts himself. The Rambam, in the same chapter (Hilchos Rotze'ach 10:8), rules that if the killer was found before the calf was beheaded, then the calf may return to graze with its herd, which means that it is permitted to benefit from the calf. If the Rambam rules that the Eglah Arufah becomes Asur b'Hana'ah at its descent to Nachal Eisan (even before it is beheaded), then it should remain Asur even if the killer is found! (The Rashba responds that he, too, was troubled by this contradiction, and after much effort had not come up with a resolution.)
(a) The KESEF MISHNEH (Hilchos Rotze'ach 10:6) and BE'ER SHEVA (Sotah 47a) answer that the case in which the killer is found differs from the normal case of Eglah Arufah. The Eglah Arufah is designated as such precisely because no killer was identified. If the person who designated the calf would have known that the killer would be found, then he never would have been Makdish the animal. Consequently, when the killer is found, the Kedushah of the animal is no longer present, for it is deemed to be "Hekdesh b'Ta'us" (Hekdesh made in error), which is not valid. This is why it is permitted to benefit from the animal even though the Rambam rules that, normally, once the calf descends into Nachal Eisan it becomes forbidden.
The Kesef Mishneh and Be'er Sheva note that TOSFOS in Chulin (82a, DH veha'Tenan) discusses and rejects this approach. They point out that the Rambam nevertheless maintains that it is a valid approach. This answer also seems to be the intention of the ME'IRI in Kidushin (57a). (See also EVEN HA'AZEL, Hilchos Rotze'ach 10:6, who discusses this answer at length.)
(b) The KEHILOS YAKOV (Sotah #7) points out that the Yerushalmi in Sotah (9:6) also rules that the Eglah Arufah becomes Asur b'Hana'ah when it descends to Nachal Eisan, and that it is not forbidden if the killer is found, which is clearly like the Rambam's ruling. However, the Bavli maintains that the two Halachos are mutually exclusive, as the Gemara in Kerisus (25a) explicitly says.
Why does the Rambam follow the Yerushalmi's view instead of the straightforward ruling of the Bavli?
The Kehilos Yakov quotes the PACHAD YITZCHAK (a composition regarding how to approach the differences between the Bavli and Yerushalmi), who cites the MAHARIK who states that the Rambam follows the rulings of the Yerushalmi when the Yerushalmi gives a simple answer and the Bavli gives a more complex answer. The Kehilos Yakov suggests that the Rambam knew that the Halachah follows the opinion that the Eglah Arufah is forbidden once it descends into Nachal Eisan, and therefore he decided to align all rulings with this opinion, once he found that the Yerushalmi says that this is possible, even though the Bavli says that these Mishnayos are arguing. (See MIRKEVES HA'MISHNEH who suggests another answer.) (Y. MONTROSE)