1) A LAW DERIVED FROM TWO SOURCES
QUESTION: The Gemara teaches that an attempt to derive a law through a "Meh Matzinu" from two Mitzvos which have this law in common to a third Mitzvah can be invalidated through a "Pircha Kol d'Hu." Even a slight difference between the target Mitzvah and the two source Mitzvos (from which the Gemara seeks to derive the law) invalidates the comparison. In contrast, when a Halachah is derived by comparing three sources, a "Pircha Kol d'Hu" does not suffice to invalidate it, unless the third source contains a unique leniency or stringency and, consequently, the law must be derived through a "Tzad ha'Shaveh" (in which case the Limud can be challenged from anything common to the sources).
What is the logic behind this distinction? It seems that the opposite should be true. It would make more sense for a Halachah that is derived from the combination of only two sources to be stronger than one that needs to be derived from three sources.
ANSWER: The HALICHOS OLAM (page 24b) explains that as long as there is no challenge that forces us to learn the Halachah through a "Tzad ha'Shaveh," the Halachah we are attempting to derive is really being learned from one source: the original Kal va'Chomer. The other sources are simply supporting the Kal va'Chomer. Obviously, a Kal va'Chomer that has two sources of support is better than one that has only one source of support. (If the derivation is challenged, however, with "Hadar Dina," then the Halachah is no longer being learned from the Kal va'Chomer but from a weak "Meh Matzinu" which relies on three sources, and, therefore, a Pircha Kol d'Hu can invalidate the teaching.) (M. KORNFELD)
2) WHAT PART OF A VINE BECOMES "KIL'AYIM"?
QUESTION: Rav Ada bar Ahavah infers that what was initially planted as Kil'ei ha'Kerem becomes prohibited, even though the tree, vines, or seeds were originally permitted (as in the case of the Isur of meat and milk).
TOSFOS (DH Ikarin) points out that the Gemara here seems to contradict the Gemara in Kesuvos (80a). The Gemara here implies that the entire vine, including the wood, becomes prohibited as Kil'ayim, and not only the fruit. However, Rav Yehudah in Kesuvos teaches that using the wood of a vine of Kil'ayim constitutes an act of Chazakah for making a Kinyan on land. However, only a permitted use of the field constitutes a valid Chazakah!
ANSWER: TOSFOS answers that there are two separate parts to a vine with regard to Kil'ayim. Although the fruit of a vine becomes forbidden as Kil'ayim when it gains more than 1/200th of its original size while planted with wheat, the branches and twigs of the vine do not become prohibited until the branches (and not just the fruit) gain more than 1/200th of their original size. (Z. Wainstein)
3) MILK SALTED WITH THE STOMACH OF A COW
QUESTION: The Mishnah teaches that if one places milk into the hide of the Keivah (abomasum) of a Kosher animal in order for the milk to curdle, the cheese that is produced is permitted unless it absorbs the taste of the meat.
RASHI (DH Harei) writes that it seems to him that a stomach that was salted with milk inside, whether the milk was placed in the stomach by a person or whether the milk was found in the stomach, is absolutely forbidden, because the salting makes the stomach and milk absorb the taste of each other. Rashi writes that if the forbidden milk later mixes with other milk used for making cheese, it is a mixture of Min b'Mino. Since the Halachah follows the view of Rebbi Yehudah (Pesachim 29b) who maintains that a mixture of Min b'Mino is prohibited even when there is a very small amount of Isur present, it follows that the mixture of milk is forbidden.
Rashi's application of Rebbi Yehudah's opinion to a case of milk salted with the stomach implies that Rebbi Yehudah maintains that even an Isur d'Rabanan is not Batel in a mixture of Min b'Mino. Is this indeed the view of Rashi?
ANSWER: The SHA'AR HA'MELECH (Hilchos Ma'achalos Asuros 15:6, DH v'Od) adduces proof from here that according to Rashi, who maintains that the Halachah follows Rebbi Yehudah, Min b'Mino is not Batel even when the Isur is only mid'Rabanan. Rashi writes that the Halachah follows Rebbi Yehudah here even though the milk in the stomach of the cow is "Chalav Shechutah," the milk that comes out of an animal after it has been slaughtered. The Gemara earlier (113b) teaches that the verse, "... in the milk of its mother" (Shemos 23:19), excludes the milk of a slaughtered animal. However, such milk is Asur mid'Rabanan (111a).
The Sha'ar ha'Melech writes that although the Gemara earlier (99b, as mentioned by the GILYON HA'SHAS here; see also Insights there) says that according to Rebbi Yehudah the forbidden brine of a non-Kosher fish is Batel in permitted brine, this does not mean that every Isur d'Rabanan is Batel even according to Rebbi Yehudah. Rather, one must say that the prohibition of fish brine is less severe than other Isurei d'Rabanan, as the Gemara states there that it is merely "Zei'ah."
The RASHASH disagrees with the Sha'ar ha'Melech's assertion that the milk found in the stomach of the cow is Chalav Shechutah. He states that since the milk now in the stomach left the udder of the mother when she was still alive, it is not considered Chalav Shechutah; the fact that the milk is collected in the stomach is equivalent to it having been collected in a dish before the mother died. Rashi himself later states this explicitly when he explains that the reason why the Gemara in Avodah Zarah (29b) permits the milk in the stomach of a Korban Olah is that it is not considered part of the mother, but rather it is "collected in her stomach as if it was collected in a dish."
This distinction is expressed by the Gemara itself (109b) when it says that milk in the stomach is considered as having been collected in its insides, in contrast to milk in the udder. Rashi (DH Zeh Kanus) writes that as soon as the milk leaves the udder of the animal it is considered "milk," whereas before it leaves the udder it is not considered milk. Therefore, the milk in the udder is Chalav Shechutah, while the milk in the stomach will be forbidden mid'Oraisa if cooked with the stomach.
However, the Rashash states that the Sha'ar ha'Melech's ruling -- that according to Rashi, the Halachah that Min b'Mino is not Batel even in a thousand times more of Heter applies also to Isurei d'Rabanan -- is correct but for a different reason. Since the milk was salted with the stomach it is only Asur mid'Rabanan, because milk and meat are forbidden mid'Oraisa only when they are actually cooked together (see above 108a, "Derech Bishul Torah"). Since Rashi is discussing an Isur d'Rabanan, it is evident that Rebbi Yehudah's ruling applies even in such a case. (D. BLOOM)
4) HALACHAH: A STOMACH THAT WAS SALTED WITH ITS MILK
OPINIONS: The Mishnah teaches that if one places milk into the hide of the Keivah (abomasum) of a Kosher animal in order for the milk to curdle, the cheese that is produced is permitted unless it absorbs the taste of the meat.
This implies that the same Halachah applies in a case in which congealed milk was found in the animal's stomach after the flesh was salted. The salting process is considered like cooking, and thus the milk and flesh of the stomach should be forbidden, since they were salted together. Is this indeed the Halachah?
(a) RASHI (DH Harei) rules that when a stomach was salted together with the milk found inside it, the stomach (and milk) are forbidden because of the mixture of meat and milk.
(b) TOSFOS (DH Hachi) cites RABEINU TAM who says that the status of the stomach depends on the density of the milk that was found inside it. If the milk is liquidy and clear, then it has the status of milk. If it is congealed, then it is viewed as a waste product and it does not prohibit the meat with which it was salted.
(c) The RAMBAM (Hilchos Ma'achalos Asuros 9:15) rules that even when a stomach is cooked with the milk that was found inside it, it is permitted. Once the milk enters the digestive system, it is considered waste and not milk. The Rambam's words imply that even liquidy, clear milk found in the stomach of the animal is considered waste and may be cooked with meat. (Z. Wainstein)
HALACHAH: The BEIS YOSEF (end of YD 87) rules like the Rambam that milk in the stomach is not considered milk, and therefore it does not become forbidden when salted with the stomach. Accordingly, in the SHULCHAN ARUCH (YD 87:10) he writes only that it is prohibited to make cheese with such "milk," since the "milk" absorbed the taste of the stomach. The "milk" itself, though, is not forbidden.
5) CHEESE MADE IN THE "KEIVAH" OF A NON-KOSHER ANIMAL
QUESTION: The Mishnah teaches that if one places milk into the hide of the Keivah (abomasum) of a Kosher animal in order for the milk to curdle, the cheese produced is permitted unless it absorbs the taste of the meat.
The Gemara in Avodah Zarah (35a, and as quoted by the Gemara here) explains that the cheese of a Nochri may not be eaten because it is made in the stomach of a non-Kosher animal.
Why does it matter that the cheese was made in the stomach of a non-Kosher animal? In both cases, it should depend on whether the cheese absorbed the taste of the meat or not! If it absorbed the taste of the meat, then in both cases it should be prohibited, while if it did not absorb the taste of the meat, it should be permitted.
(a) TOSFOS (116a, DH ha'Ma'amid) explains that there is a difference between cheese made in the stomach of a Kosher animal and cheese made in the stomach of a non-Kosher animal. Cheese made in the stomach of a Kosher animal is forbidden only mid'Rabanan, because the stomach and the milk were not actually cooked together. Cheese made in the stomach of a non-Kosher animal, in contrast, is forbidden not because of an Isur d'Rabanan of meat and milk, but because of an Isur d'Oraisa of non-Kosher meat.
(b) The RAMBAM (Hilchos Ma'achalos Asuros 9:16) answers that there is a fundamental difference between the prohibition of meat with milk and all other prohibitions (such as the prohibition of non-Kosher meat). When a prohibited food is used as a Ma'amid for other food, the taste of the prohibited food does not become Batel b'Shishim. This is why the cheese of Nochrim is prohibited even though the taste of non-Kosher meat is not discernible in it. However, when cheese is made in the stomach of a Kosher animal, since the meat by itself is not a prohibited food it will prohibit the cheese only if the taste of meat is discernible. (Z. Wainstein)