1) "DAVAR SHE'EINO MISKAVEN" AND CUTTING OFF A LEPROUS "NEGA"
QUESTION: The Gemara says that according to Rebbi Yehudah, the Torah forbids performing Milah when there is a leprous Nega that is Tamei on the place of the Milah. Even though one does not have intention (Eino Miskaven) to cut off the Nega, a Davar she'Eino Miskaven is forbidden mid'Oraisa according to Rebbi Yehudah. (The Gemara concludes that even according to Rebbi Shimon it is prohibited, because it is a Pesik Reishei).
Why does the Gemara say that according to Rebbi Yehudah it is forbidden mid'Oraisa to perform a Davar she'Eino Miskaven and cut off the Nega? We find that Rebbi Yehudah normally prohibits a Davar she'Eino Miskaven only mid'Rabanan and not mid'Oraisa. (See Rashi 121b, DH l'Fi Tumo; Tosfos 41b, DH Meicham.)
ANSWER: The MAHARSHAL explains that only with regard to the laws of Shabbos does Rebbi Yehudah say that a Davar she'Eino Miskaven is forbidden mid'Rabanan. As TOSFOS (41b) explains, with regard to Shabbos the Torah requires explicit intent to perform the Melachah (Meleches Machsheves) in order to be Chayav. With regard to other prohibitions of the Torah (such as the case here of cutting off a Nega) which are not regulated by the condition of Meleches Machsheves, a Davar she'Eino Miskaven is forbidden mid'Oraisa.
2) A MOHEL WHO REMOVES A LEPROUS "NEGA" WITHOUT INTENT
QUESTION: RASHI (DH b'Omer la'Kotz) writes that if an uncircumcised, adult Jewish man had a leprous Nega in the place of his Milah and he appointed someone else to perform Milah (and thereby to cut off the Nega as well), the appointed Mohel is Chayav for cutting off a Nega Tamei. The Mohel is considered as though he had intention to cut the Nega off, since the man who appointed him certainly had an interest in getting rid of the Nega (because he wanted to become Tahor). Similarly, if a father appoints a Mohel to perform Milah on his child and the father is present during the Milah, since the father certainly intends to remove the Nega from his son while the Milah is performed, the Mohel is Chayav as if he himself intended to transgress the Isur of removing a Nega Tamei (Rashi, DH v'Iy Ika Acher).
Why, when one person has in mind to remove a Nega and he asks a Mohel to perform Milah for him, is the Mohel's act considered an intentional removal of a Nega Tamei? The Mohel who performs the Milah does not intend to remove the Nega, and the person who does intend to remove the Nega does not perform any action! The Mohel should not be Chayav because he does not have intention to cut off the Nega, and the person who appointed him should not be Chayav because a Shali'ach cannot be appointed to commit a transgression ("Ein Shali'ach l'Devar Aveirah") on his behalf. Only when the Mohel intends to cut off the Nega should he be Chayav.
Also, Rashi (DH v'Iy Ika Acher) implies that when a father appoints a Mohel to perform Milah on his child, the Mohel is Chayav if "the father is standing there." What difference does it make if the father is present or not at the time that the Mohel performs Milah on his son?
ANSWER: The MISHNEH L'MELECH (10:1) and MINCHAS CHINUCH (#584) explain that as long as the father (or, in the first case of the Gemara, the person upon whom the Milah is performed) is present at the time of the Milah, the Mohel cannot avoid having in mind to satisfy whatever intentions the father has at the time the Milah is performed. Since the Mohel knows that the father will be pleased by the removal of the Nega, he inevitably intends to remove the Nega as well. Only if the father is not there at all does the Mohel perform the Milah exclusively in order to remove the Orlah, without intention to remove the Nega.
Rashi derives this point from the Gemara's statement that when a person has a Nega on his own Orlah, he inevitably intends to remove the Nega at the moment he performs the Milah. It is clear from the Gemara that even if someone else performs Milah on him, he does it with intent to remove the Nega. Apparently, the Mohel's intentions are controlled by the person who orders the Milah. However, if Milah is performed on a person's son and there is a Nega on the Orlah, the Gemara says that it is possible for the Mohel to perform the Milah exclusively for the sake of the Mitzvah of Milah. Apparently, his intentions are not controlled by the client in that case.
To resolve this apparent contradiction, Rashi concludes that as long as the person who orders the Milah is present at the time, his will determines the Mohel's intentions. When the Milah is performed on his own body, he is obviously present, but when it is performed on his son, he does not necessarily need to be present.
3) REMOVING A LEPROUS "NEGA" INDIRECTLY
QUESTION: Even though one is prohibited from removing a Nega Tamei from one's body intentionally, the Gemara concludes that one is permitted to cause a Nega to be removed from his skin indirectly, such as by carrying an object on one's shoulder that rubs against and removes a Nega there. This is permitted even if it is a Pesik Reishei that the object on the shoulder will remove the Nega.
If one is permitted to remove the Nega indirectly even when doing so is a Pesik Reishei, then why does the Gemara need to find a source (at the beginning of this Daf) to teach us that one is permitted to cut off an Orlah that has a Nega on it? According to both Rebbi Shimon and Rebbi Yehudah, one should be permitted to cut off the Orlah that has a Nega on it because one does not have intention to remove the Nega, even though it is a Pesik Reshei.
(a) The RAMBAN answers that, indeed, now that we know that one is permitted to remove a Nega indirectly even though the act is a Pesik Reishei, the source that teaches that Milah may be done even when there is a Nega applies when one intends to remove the Nega -- such as when a father performs Milah on his son. Even though the father has intention to remove the Nega so that his son will be Tahor, he is permitted to do so since there is no one else available to do the Milah. (If someone else is available, the father must appoint the other person to perform the Milah rather than do it himself, since it is possible to avoid intentionally cutting off a Nega, just as the Gemara concludes according to Abaye.) Similarly, when a person needs to perform Milah on himself, he may do so even though he has intention to remove the Nega.
(b) The RASHBA explains that one is permitted to remove a Nega with a Pesik Reishei only when he has no intention to perform an act of cutting. He simply places a burden on his shoulder. In the case of Milah, however, the person has intention to do an act of cutting; he just does not have intention to do an act of cutting off the Nega but only to cut off the Orlah (in order to fulfill the Mitzvah of Milah). In such a case, since the person has intention to cut, the removal of the Nega with a Pesik Reishei is forbidden. Therefore, a verse is needed to teach that when there is a Mitzvah of Milah to perform, one is permitted to cut off a Nega on the Orlah even though he has intention to perform an act of cutting.
(According to the Rashba, it makes no difference whether someone else is available to perform the Milah or not, since in any case the prohibition of cutting off a Nega through a Pesik Reishei cannot be avoided.)
4) DOING "MELACHAH" FOR A BABY WHOSE MILAH IS ON SHABBOS
QUESTION: The Mishnah states that all actions necessary to perform the Milah are permitted on Shabbos. If the medicine for the child was not prepared and ground before Shabbos, one should chew it with his teeth in order to prepare it with a Shinuy.
Why must one do a Shinuy? Normally, in a situation of Piku'ach Nefesh, one is permitted to do a Melachah on Shabbos (Shabbos is "Hutrah") and there is no need to perform a Melachah through the use of a Shinuy!
ANSWER: TOSFOS (133b, DH Lo'es) emphasizes that even though this is a situation of Piku'ach Nefesh, one must try to do a Shinuy if possible when one must perform a Melachah. The SHACH (YD 266:3) explains that since a person knows in advance that the child will be in a state of Piku'ach Nefesh, the allowance to perform Melachah on Shabbos is not as absolute as it is in a normal case of Piku'ach Nefesh, and therefore one must do the Melachah with a Shinuy. (The SEFAS EMES here offers the same explanation. See Insights to Shabbos 128:3 and Nidah 38:5 with regard to doing Melachah on Shabbos with a Shinuy for a woman in labor.)
5) "ZEH KELI V'ANVEIHU" -- THE CONCEPT OF BEAUTIFYING A MITZVAH
OPINIONS: The Gemara cites a Beraisa that says that when a Milah is performed on Shabbos, after the Milah itself the Mohel must go back and cut off the Tzitzin ha'Me'akvin, any pieces of skin that remain that cover a majority of the Atarah after the Orlah was cut off (the Milah is not valid if such Tzitzin remain). This requirement applies whether or not the Mohel is still involved in the Milah. In contrast, the Mohel does not go back and cut off the Tzitzin she'Einan Me'akvin (that is, those Tzitzin that do not invalidate the Milah) if he is no longer involved in the Milah.
The Gemara explains that this depends on a dispute between Rebbi Yosi and the Chachamim with regard to the removal and replacement of the Lechem ha'Panim in the Beis ha'Mikdash. According to the Chachamim, the Kohanim who bring in the new Lechem ha'Panim must replace the old Lechem ha'Panim immediately when the old Lechem ha'Panim are removed in order for it to be considered "Tamid." This is because the Torah requires that there be Lechem ha'Panim on the Shulchan at all times ("Tamid"). According to Rebbi Yosi, the new Lechem ha'Panim may be placed on the Shulchan later on the same day, and this also fulfills the requirement of "Tamid."
According to Rebbi Yosi, acts done at different times are still considered to be parts of one act, and that is why the Lechem ha'Panim are considered to be on the Shulchan "Tamid." In contrast, the Chachamim maintain that two acts are considered to be parts of one long act only when they are done in immediate succession, with no delay between them.
In what way does this argument relate to cutting off the Tzitzin she'Einan Me'akvin on Shabbos?
(a) RASHI and most Rishonim explain that the reason the Mohel must go back to remove Tzitzin she'Einan Me'akvin is because of the requirement to beautify the performance of Mitzvos, which is derived from the verse, "Zeh Keli v'Anveihu," as the Gemara mentions. On Shabbos, though, since the presence of these Tzitzin does not invalidate the Milah, one may not do a Melachah merely to fulfill the concept of beautifying the Mitzvah. However, if it is done as part of one long action of performing the Milah, then it may also be done on Shabbos, because it is considered part of the Milah.
(b) The RAMBAM (Hilchos Milah 2:4 and 6) rules that a Mohel is not required to go back and cut off the Tzitzin she'Einan Me'akvin even during the week. (This interpretation of the Rambam's words is according to the conclusion of the Kesef Mishneh.)
The BRISKER RAV (Hilchos Chanukah 4:1) and the BEIS HA'LEVI (2:47) explain that the Rambam learns the Gemara the same way as RABEINU CHANANEL. Rabeinu Chananel writes that one who stops performing a Mitzvah is no longer required to beautify that Mitzvah. This means that beautifying a Mitzvah is meaningful only when it is done as part of the performance of the Mitzvah. After the Mitzvah has been performed, there is no point in beautifying it. The beautification is in the performance, or the act, of the Mitzvah, and not in the object, or the result, of the Mitzvah that remains when the performance of the Mitzvah is completed. Therefore, after the Milah is performed, there is no point in making the Milah look nice because of the requirement to beautify Mitzvos. Only during the act of Milah itself is there a requirement to make it look nice.