1) BUYING AN OBJECT FOR THE MISHKAN FROM A NOCHRI
QUESTION: The Gemara (23b) quotes Shila who explains that according to Rebbi Eliezer, when the Torah says "Daber El Bnei Yisrael v'Yikchu" -- "Speak to the Jewish people and they will take..." (Bamidbar 19:2), the Torah is teaching that the Parah Adumah must be purchased from a Jew and not from a Nochri. The Gemara questions this from the incident of Dama ben Nesinah. The Chachamim purchased from Dama ben Nesinah, a Nochri, a precious stone for the Efod of the Kohen Gadol, even though the verse says "Daber El Bnei Yisrael v'Yikchu..." (Shemos 25:2) with regard to the acquisition of the materials used for the Mishkan. The Gemara answers that when the Torah lists the materials, it mentions "Avnei Shoham" (Shemos 25:7), the stones set on the Efod, without the word "and" (the letter "Vav"). This shows that the stones of the Efod are not part of the list and do not need to be acquired from a Jew.
The Gemara rejects this explanation, because the next words in the same verse are "v'Avnei Milu'im," with the conjunctive "Vav." This shows that the stones indeed were part of the previous list.
What is the Gemara's question from the mention of the Avnei Milu'im in the verse? The stone of Dama ben Nesinah was being purchased for use on the Efod. The stones of the Efod were the Avnei Shoham (as the verse states in Shemos 28:9). The Avnei Milu'im, in contrast, were used for the Choshen and not for the Efod (as the verse states in Shemos 28:17). Perhaps the Avnei Milu'im indeed could not be acquired from a Nochri, while the Avnei Shoham could be acquired from a Nochri, and that is why the Chachamim purchased the stone from Dama ben Nesinah! (TOSFOS)
ANSWERS:
(a) TOSFOS (DH v'Avnei) answers that when the Gemara says that Dama's stone was used for the Efod, it does not mean the Efod itself, but rather it means that the stone was used for the Choshen that was attached to the Efod. (The RAMBAN in Shemos 25:7 makes a similar statement with regard to the Gemara in Gitin 68a that says that the Shamir was used for the stones of the Efod.) Tosfos proves this from the Yerushalmi in Pe'ah which states explicitly that the stone which the Chachamim purchased from Dama ben Nesinah was a Yashpeh stone (which is one of the stones used for the Choshen).
The RITVA, however, rejects this answer. If the question of the Gemara is based on the Yerushalmi, then the Gemara also should mention that the stone in question was used for the Choshen and not for the Efod! (Some Rishonim cite a different Girsa of the Gemara in order to answer this question.)
(b) The TARGUM YONASAN (to Shemos 25:7) writes that "Avnei Shoham" and "Avnei Milu'im" are different names for the same stones. They refer to all of the stones that were used for the Choshen and Efod. The Ritva says that according to this translation, the Gemara's question is clear.
Although RASHI on the Chumash there writes that the Avnei Shoham were used for the Efod and the Avnei Milu'im for the Choshen, he might agree that "Avnei Milu'im" is a general term which refers to the stones of the Efod as well as those of the Choshen. This may be inferred from his translation of "Milu'im." Rashi translates "Milu'im" as stones that fill the groove that were made for them. The Ramban there asks that according to this definition, "Avnei Milu'im" should include the stones of the Efod as well. Perhaps Rashi indeed understands that the term "Avnei Milu'im" refers to both types of stones. Accordingly, the Gemara is easily understood, since the words "v'Avnei Milu'im" teach that even the stones of the Efod cannot be purchased from a Nochri. (The Ramban himself also concludes that it is possible that the words "Avnei Milu'im" refer to the stones of the Efod as well as to those of the Choshen, even according to his definition of "Milu'im.")
(c) RAV REUVEN MARGOLIYOS in NITZOTZEI OR cites the SEFER ASPAKLARIYA HA'ME'IRAH (on the Zohar) who suggests that even if the words "v'Avnei Milu'im" refer only to the stones of the Choshen, the Gemara is still able to infer from the "Vav" that both the Avnei Shoham and the Avnei Milu'im are included in the requirement that they must be acquired from Jews. The reason for this is that the words in the verse seem to be written in an incorrect order. The verse says, "Avnei Shoham and Avnei Milu'im, for the Efod and for the Choshen." However, it would be more logical for the verse to say, "Avnei Shoham for the Efod, and Avnei Milu'im for the Choshen." The fact that the Torah writes "for the Efod" after it mentions the Avnei Milu'im implies that both sets of stones share the same laws. Therefore, if the Avnei Milu'im may not be purchased from a Nochri (because the Torah says "v'Avnei Milu'im" with a "Vav"), then the Avnei Shoham also may not be purchased from a Nochri.
2) THE MOTHER OF THE "PARAH ADUMAH"
QUESTION: The Gemara asks why one is permitted to purchase a Parah Adumah from a Nochri. Why is there no concern that the animal became disqualified from being used as a Parah Adumah because of Revi'ah? Even if a Jew watches the Parah Adumah from the moment that it is born, there still should be a concern that perhaps the Nochri was Rove'a the mother, thereby causing all of its offspring to be disqualified, as Rebbi Eliezer rules (according to Rav Huna bar Chinena).
Why does the Gemara ask that we should be concerned that the Nochri was Rove'a the mother of the Parah Adumah? The Gemara (22b) teaches that if a Nochri is Rove'a a female animal, that animal becomes an Akarah and can no longer bear offspring. The mother of the Parah Adumah, therefore, certainly did not suffer Revi'ah, for it conceived and gave birth to a Parah Adumah! (RITVA)
ANSWERS:
(a) The RITVA explains that an animal will not always become an Akarah as a result of Revi'ah. When the Gemara earlier says that Revi'ah will cause the animal to become an Akarah, it means that most of the time it will cause an animal to become an Akarah. There remains a chance that it will be able to give birth.
(b) RAV YAKOV EMDEN suggests that the Gemara's question is that perhaps the Nochri was Rove'a the grandmother of the Parah Adumah while it was pregnant with its offspring (the mother of the Parah Adumah). Although the Revi'ah will make the grandmother an Akarah, the mother (who is considered to have suffered Revi'ah as well and is thus disqualified) does not become an Akarah as a result of the Revi'ah, since no physical act was done to it.
3) THE GRANDMOTHER OF THE "PARAH ADUMAH"
QUESTION: The Gemara states that if a Jew has watched the Parah Adumah from the time of its conception, as well as its mother from the time of its conception, then there is no concern that perhaps the Nochri was Rove'a the grandmother.
Why is there no concern about Revi'ah of the grandmother? The likelihood that a Nochri was Rove'a the grandmother is exactly the same as the likelihood that a Nochri was Rove'a the mother or the daughter. Why should there be any less concern that the Nochri was Rove'a the grandmother?
ANSWER: The TOSFOS RID explains that the Gemara does not mean that there is less likelihood that the Nochri was Rove'a the grandmother. Rather, the Gemara means that even if the grandmother suffered from Revi'ah, that is not sufficient reason to disqualify the granddaughter from being used as a Parah Adumah.
The logic for this (as explained by RAV NISAN ZAKS in his footnotes to the Tosfos Rid) is as follows. The reason the Parah Adumah is disqualified if the Nochri was Rove'a its mother is that it is disgraceful to use such an animal for a holy purpose (see Temurah 30b). However, if the Nochri was Rove'a the grandmother, it is not disgraceful to use the granddaughter as a Parah Adumah, since she is two generations away from the animal that suffered Revi'ah. (According to the other opinion in Temurah, which maintains that when the Nochri was Rove'a the mother the daughter is disqualified because of "Zeh v'Zeh Gorem," the Pesul of Revi'ah of the grandmother does not disqualify the granddaughter because the granddaughter is three parts Kasher and only one part Pasul. That is, it has three Kasher forebears and one Pasul forebear.)

24b----------------------------------------24b

4) WHEN A COW COMES OF AGE
QUESTIONS: Rebbi Yochanan teaches that there is an age limit for an animal with regard to whether there is a concern that a Nochri was Rove'a it. When the animal is less than three years old, Revi'ah will render it an Akarah (sterile), and, therefore, there is no fear that a Nochri would damage his own animal in such a way. Consequently, one is permitted to buy the animal from the Nochri for use as a Korban. In contrast, an animal that is more than three years old does not become an Akarah through Revi'ah, and, therefore, one may not purchase it from a Nochri, out of concern that the Nochri was Rove'a it and thereby invalidated it from being brought as a Korban.
(a) The Mishnah (14b) teaches that in a place where it is the common practice to sell animals to Nochrim, one is permitted to sell animals to them. This implies that there is concern that one might transgress the prohibition of "Lifnei Iver" by selling an animal to a Nochri, since he is not suspected of committing Revi'ah with his own animal (because Revi'ah might cause the animal to become an Akarah). According to Rebbi Yochanan, why is one permitted to sell an animal to a Nochri? Even if the animal is now less than three years old, it will eventually grow older, and thus there should be a concern that selling an animal to a Nochri will cause him, eventually, to transgress the Isur of Revi'ah!
(b) It seems that the intention of Rebbi Yochanan's distinction between animals of different ages is to answer the contradiction between the Mishnah (22a), which teaches that one may not park his animal at the inn of a Nochri, and the Beraisa (22b), which teaches that one is permitted to purchase an animal from a Nochri for use as a Korban. Accordingly, Rebbi Yochanan is expressing not only a stringency in disallowing a Jew from purchasing from a Nochri an animal (for use as a Korban) that is more than three years old, but he is also being lenient with regard to parking a Jew's animal at the inn of a Nochri! Rebbi Yochanan maintains that although the animal belongs to a Jew, the Nochri still will refrain from Revi'ah since he is afraid that he will be caught by the Jew.
The Beraisa (22b) teaches that one may not entrust his animal with a Nochri out of concern for Revi'ah. The Beraisa does not distinguish between animals of different ages. According to the apparent intention of the words of Rebbi Yochanan, why should one be prohibited to entrust an animal that is less than three years old with a Nochri? It should be no different from leaving one's young animal with a Nochri innkeeper!
ANSWERS:
(a) There are different approaches in the Rishonim to explain why Rebbi Yochanan permits the sale of an animal to a Nochri.
1. TOSFOS (23a, DH Ravina) explains that Rebbi Yochanan was stringent only with regard to purchasing an animal from a Nochri for a Korban, when the animal is older than three years. This is because of the necessity to be more careful about an animal that will be used for a Korban. (Tosfos (22b, DH u'Reminhu) proposes another reason for being stringent with regard to the purchase of an animal for a Korban. He says that perhaps the Nochri knew that he was going to sell the animal, and therefore he did not refrain from Revi'ah.) However, with regard to selling an animal to a Nochri, there is no concern for Revi'ah even when the animal is more than three years old, since the Nochri will refrain from Revi'ah even when it is less likely that Revi'ah will cause the animal to become sterile.
2. TOSFOS RABEINU ELCHANAN (23a) writes that Rebbi Yochanan's statement was made only with regard to a place where it is not the common practice to sell animals to Nochrim. Rebbi Yochanan means that even in such a place one is permitted to purchase an animal from a Nochri to be used as a Korban when the animal is less than three years old. In a place where it is common practice to sell animals to Nochrim, animals may be purchased from Nochrim even when the animals are more than three years old.
(b) There are different approaches in the Rishonim to explain Rebbi Yochanan's intention.
1. TOSFOS (DH Rebbi Yochanan) and the RASHBA indeed understand the words of Rebbi Yochanan as explained above. Rebbi Yochanan is stringent not only with regard to purchasing older animals for use as Korbanos, he is also lenient with regard to parking a young animal at the inn of a Nochri. According to Tosfos, it seems that the Beraisa which prohibits entrusting one's animal with a Nochri indeed refers only to older animals; it would permit one to entrust an animal less than three years old with a Nochri shepherd.
2. However, RASHI (DH Rebbi Yochanan) and TOSFOS RABEINU ELCHANAN imply that Rebbi Yochanan does not intend to answer the contradiction between the Mishnah and the Beraisa. Rather, Rebbi Yochanan is teaching a stringency with regard to purchasing an animal for a Korban, and he is not addressing the Halachah of the Mishnah. Rebbi Yochanan agrees that a Nochri is suspected of Revi'ah with a Jew's animal entrusted in his care even when the animal is less than three years old.

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