1) THE DISCUSSION OF "TZOMES HA'GIDIN"
QUESTION: The Mishnah teaches the laws that apply to an animal with a broken leg bone, and an animal with a missing Tzomes ha'Gidin.
Why is this Mishnah placed here, in the chapter that discusses the laws of a fetus? It belongs in the previous chapter, "Elu Tereifos," that discusses the blemishes that render an animal a Tereifah!
ANSWERS:
(a) The RAMBAM (in Perush ha'Mishnayos) explains that this Mishnah is placed here because of the last law that it teaches: "If the bone is broken but most of the flesh around it is still intact, the Shechitah is Metaher it." This law is similar to the law discussed in the preceding Mishnayos with regard to when the Shechitah of a cow is Metaher the fetus inside it.
(b) The TIFERES YISRAEL explains that this Mishnah is located here because the Mishnah earlier teaches that if a protruding limb of a fetus was cut off before the cow's Shechitah, the remaining part of the fetus inside the womb may be eaten, regardless of where the cut was made on the limb of the fetus (the fetus is permitted even if it is a Tereifah). The Mishnah here points out that this does not apply to a limb that was cut off of a grown cow. A cow would not be Kosher if its limb was cut off at any point above the Arkuvah (see following Insight).
2) HALACHAH: THE "ARKUVAH" AND "TZOMES HA'GIDIN"
OPINIONS: The Mishnah teaches that when an animal's hind leg was cut anywhere below the Arkuvah, the animal is Kosher. When the cut was above the Arkuvah, the animal is a Tereifah.
There are two opinions in the Gemara with regard to which Arkuvah the Mishnah is discussing. Rav Yehudah says that the Mishnah is discussing the lower Arkuvah (knee joint), which is below the Tzomes ha'Gidin. Ula says that the Mishnah is discussing the upper Arkuvah, which is above the Tzomes ha'Gidin. According to Ula, even if the bone attached to the upper Arkuvah is severed above the Tzomes ha'Gidin (but below the upper Arkuvah), the animal is Kosher.
Which opinion does the Halachah follow?
(a) RASHI (DH v'Chi) rules in accordance with Rav Yehudah. If the bone is severed from the lower Arkuvah and upward, then the animal is a Tereifah. Similarly, the removal of the Tzomes ha'Gidin renders the animal a Tereifah.
The ROSH (4:7) quotes the SEFER HA'TERUMAH who accepts Rashi's opinion and rules that the Arkuvah mentioned in the Mishnah is the lower Arkuvah, and such was the custom in Ashkenaz and Tzarfas (Germany and France).
(b) The ROSH quotes the RIVA who asserts that the Halachah follows the second, more lenient opinion, as is evident from the conclusion of the Gemara. The RIVA writes that RABEINU YITZCHAK BEN YEHUDAH permitted an animal that had a leg that was severed above the Tzomes ha'Gidin but below the upper Arkuvah. He suggests that the RIF also seems to rule this way, since the Rif omits the first opinion and mentions only the second opinion.
This is also the view of the RAMBAN. However, the Ramban points out that this opinion leads to a Halachic anomaly. When the Tzomes ha'Gidin of the leg of an animal was removed or injured, rendering the animal a Tereifah, it should be possible to make the animal Kosher again by cutting the leg off at the bone above the Tzomes ha'Gidin, and below the upper Arkuvah! Indeed, the Ramban suggests that this method could be used to "fix" an animal from which the Tzomes ha'Gidin was removed. (The Ramban points out that this procedure is effective only when it is done while the animal is still alive, before the Shechitah.) (See the following Insight for a discussion of this Halachah.)
The Rosh disagrees with the Ramban's reasoning and maintains that the status of Tereifah is irreversible. Once an animal becomes a Tereifah, it cannot become permitted.
HALACHAH: The SHULCHAN ARUCH (YD 55:1) records both opinions. The REMA writes that the practice in all of Ashkenaz and Tzarfas is to follow the stringent opinion. (Z. Wainstein)
3) REVERSING THE STATUS OF "TEREIFAH"
QUESTIONS: The Mishnah teaches that when an animal's hind leg was cut anywhere below the Arkuvah, the animal is Kosher. When the cut was above the Arkuvah, the animal is a Tereifah.
There are two opinions in the Gemara with regard to which Arkuvah the Mishnah is discussing. Rav Yehudah says that the Mishnah is discussing the lower Arkuvah (knee joint), which is below the Tzomes ha'Gidin. Ula says that the Mishnah is discussing the upper Arkuvah, which is above the Tzomes ha'Gidin. According to Ula, even if the bone attached to the upper Arkuvah is severed above the Tzomes ha'Gidin (but below the upper Arkuvah), the animal is Kosher.
The ROSH (4:7) infers from the words of the RIF, who omits the first opinion and mentions only the second opinion, that the Rif rules like the second opinion (see previous Insight). This is also the view of the RAMBAN. The Ramban points out that this opinion leads to a Halachic anomaly. When the Tzomes ha'Gidin of the leg of an animal was removed or injured, rendering the animal a Tereifah, it should be possible to make the animal Kosher again by cutting the leg off at the bone above the Tzomes ha'Gidin, and below the upper Arkuvah! Indeed, the Ramban suggests that this method could be used to "fix" an animal from which the Tzomes ha'Gidin was removed. (The Ramban points out that this procedure is effective only when it is done while the animal is still alive, before the Shechitah.)
The Rosh disagrees with the Ramban's reasoning and maintains that the status of Tereifah is irreversible. Once an animal becomes a Tereifah, it can no longer be permitted.
The Ramban's opinion is problematic for several reasons.
1. The Gemara earlier (54a) states that when an animal received a fatal blow in its Gid ha'Nasheh, it is not a Tereifah, because the Chachamim had a tradition that there exists a medication that can be applied to heal the wound. The Gemara there shows that a wound that can be healed does not render the animal a Tereifah! How, then, can the removal of the Tzomes ha'Gidin render the animal a Tereifah if that status can be remedied by cutting the bone above that area?
2. The Gemara in Bava Kama (41a) seems to contradict the Ramban's opinion. The Mishnah there teaches that a Shor Tam that kills a person is put to death, and a Shor Mu'ad that kills a person not only is put to death, but the owner must pay "Kofer" to the family of the victim. The Gemara asks how is possible for a Shor Tam that kills a person to become a Mu'ad? If the Shor is put to death the first time that it kills a person, then it will never be able to kill a person three times!
According to the Ramban, there is a simple answer to the Gemara's question there. A Shor Tam that is a Tereifah is not put to death for killing a person. The Gemara in Sanhedrin (78a) teaches a principle that in a case in which a person is exempt from Misah for killing another person, an animal is also exempt from Misah for killing. Since a person who is a Tereifah is not put to death, an animal that is a Tereifah is not put to death. Accordingly, when a Shor Tam was a Tereifah due to the removal of its Tzomes ha'Gidin, it is not put to death. If, after killing two people, its bone above the Tzomes ha'Gidin is cut, the animal becomes Kosher and when it then kills a third person, it is a Shor Mu'ad that must be put to death! Why, according to the Ramban, does the Gemara in Bava Kama not suggest this answer? (TESHUVAS AMUDEI OR #48)
ANSWER: The ACHIEZER (1:12:5, DH uv'Emes) answers that it must be that the Ramban maintains that there is a difference between a wound that can be healed through medication and a wound that can be altered from the status of a Tereifah through another act. RAV SHLOMO HEIMANN zt'l explains that an animal that cannot survive for twelve months in its present state is considered a Tereifah. An animal that can survive for twelve months once its leg is amputated is considered a different animal. In contrast, the animal that lives for twelve months because of medication is considered the same animal that was sick. When medication enables an animal to survive for twelve months, this shows retroactively that the animal was not a Tereifah.
However, this logic applies only to cases of Tereifos in animals, but not to Tereifos in humans. Tereifos in animals are derived from the Halachah l'Moshe mi'Sinai, while Tereifos in humans (such as the law that a person who murdered a Tereifah person, or a Tereifah person who murdered a healthy person, is not punished with the death penalty) is not a Halachah l'Moshe mi'Sinai but rather it is based on the logic that when a "Gavra Ketila" (a dead person; i.e. one who is going to die soon) kills or is killed, the perpetrator is exempt from the death penalty. Therefore, a human whose status as a Tereifah could be altered by amputating the leg above the Tzomes ha'Gidin is not considered a "Gavra Ketila" and is not a Tereifah. If he murders another person, he is liable for the death penalty. Accordingly, when a bull with the same condition killed, the bull is not considered a Tereifah with regard to being exempt from the death penalty (even though such an animal is forbidden to be eaten before the amputation). (D. BLOOM)

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