1) RECITING PRAYERS INAUDIBLY
QUESTION: The Mishnah (20b) states that a deaf person may not read the Megilah, even b'Di'eved. In the Gemara, Rav Masnah attributes the Mishnah to Rebbi Yosi. Rebbi Yosi's opinion appears in Berachos (15a), where he says that one who reads the Shema without hearing it does not fulfill his obligation. Rebbi Yehudah there disagrees with Rebbi Yosi and says that one fulfills his obligation (apparently, even l'Chatchilah) even though he does not hear what he says. Since Rebbi Yosi maintains that one must hear what he says (even b'Di'eved), a deaf person may not read the Megilah.
The Gemara engages in a lengthy discussion in which it cites several Mishnayos and Beraisos which discuss cases in which one recites a prayer or blessing inaudibly. The Gemara proposes suggestions for which Tana is the author of each one. In the end of its discussion, the Gemara introduces a third Tana, Rebbi Elazar ben Azaryah, who maintains that one who reads the Shema without hearing what he says fulfills his obligation b'Di'eved. The Gemara concludes that Rebbi Yehudah agrees with the opinion of Rebbi Elazar ben Azaryah.
In the first stage of the Sugya, when the Gemara assumes that Rebbi Yehudah does not agree with Rebbi Elazar ben Azaryah, RASHI (DH l'Olam Rebbi Yehudah) writes that the Tana of the Mishnah here is Rebbi Yosi, as Rav Masnah originally suggests, and thus a deaf person may not read the Megilah even b'Di'eved.
In the end of the Sugya, when the Gemara concludes that Rebbi Yehudah agrees with Rebbi Elazar ben Azaryah, RASHI (DH Afilu Teima Rebbi Yehudah) writes that the author of the Mishnah here is not Rebbi Yosi but Rebbi Yehudah, and the Mishnah means that a deaf person may not read the Megilah l'Chatchilah but he may read it b'Di'eved. Hence, Rav Masnah's original suggestion is incorrect.
Why does Rashi change this point from the first stage of the Sugya to the second stage? Even in the second stage of the Gemara, the Tana of the Mishnah here could be Rebbi Yosi! (MAHARSHA; see MAHARATZ CHAYOS.)
ANSWERS:
(a) Rashi understands that when the Gemara introduces the opinion of Rebbi Elazar ben Azaryah (who says that one fulfills his obligation b'Di'eved when he does not hear what he says), the Gemara's intention is to defend the statement of Rav Masnah. How does the Gemara support his statement?
The Gemara first asserts that Rebbi Elazar ben Azaryah of the Beraisa is the only Tana who maintains that one fulfills his obligation b'Di'eved when he does not hear what he says. By demonstrating that there is no Tana in any Mishnah (other than Rebbi Yosi in the Mishnah here) who is of that opinion, the Gemara proves that it must be that the Tana of the Mishnah in Terumos who says that one fulfills his obligation b'Di'eved is none other than Rebbi Yosi. It is unlikely that the Tana of the Mishnah in Terumos is a Tana who is not mentioned in any other Mishnah (but only in a Beraisa, such as Rebbi Elazar ben Azaryah). Similarly, the Gemara defends Rav Masnah by showing that Rebbi Yosi is the only Tana in a Mishnah who is of the opinion that one fulfills his obligation b'Di'eved. Accordingly, the Tana of the Mishnah here is most likely Rebbi Yosi (and the Mishnah is teaching that a deaf person may not read the Megilah even b'Di'eved).
When the Gemara concludes that Rebbi Yehudah agrees with Rebbi Elazar ben Azaryah, Rashi understands that the Gemara is refuting Rav Masnah conclusively. That is, each of the other Mishnayos could be either Rebbi Yehudah or Rebbi Yosi, and thus it is incorrect to assert that the Mishnayos can be only Rebbi Yosi.
(b) However, the suggestion that the Mishnah follows the view of Rebbi Yehudah (who says that one fulfills his obligation b'Di'eved when he does not hear what he reads) seems to be somewhat forced. After all, if the Mishnah maintains that a deaf person fulfills his obligation b'Di'eved, then it is necessary to differentiate between the three groups of people who are listed together in the Mishnah (Cheresh, Shoteh, Katan), as the Gemara said earlier ("Ha k'd'Isa..."). The fact that they are listed together, however, implies that the same Halachah applies to all of them. Why, then, does the Gemara prefer to reject Rav Masnah's suggestion and attempt to establish the Mishnah like the opinion of Rebbi Yehudah?
TOSFOS (19b, DH v'Dilma) explains that the Gemara prefers that the Mishnah follow the opinion of Rebbi Yehudah because of the tradition that the Halachah is in accordance with Rebbi Yehudah of the Mishnah in Berachos (15a).
However, at this stage, the Gemara suggests that Rebbi Yehudah of the Mishnah in Berachos allows a deaf person to read l'Chatchilah. It is his rebbi, Rebbi Elazar ben Azaryah, who allows it only b'Di'eved but not l'Chatchilah. There is no reason to "force" the Mishnah here to conform with the opinion of Rebbi Elazar ben Azaryah, since his opinion is not the Halachah. For this reason, Rashi here does not entertain the possibility that the Mishnah is Rebbi Elazar ben Azaryah. Rather, Rav Masnah was correct; the Mishnah is the opinion of Rebbi Yosi. (M. Kornfeld)

20b----------------------------------------20b

2) TWO MISHNAYOS THAT SHOULD BE ONE
QUESTIONS: The Mishnah (20a) lists five Mitzvos that may be done only after sunrise. These include Mikra Megilah, Milah, Tevilah, Haza'ah, and Tevilah of a Shomeres Yom k'Neged Yom. The Mishnah (20b) then says that any Mitzvah which must be done during the day may be done at any time during the day. The Mishnah mentions the Mitzvah of Mikra Megilah (as it mentions in the previous Mishnah), and it proceeds to list twenty other Mitzvos, none of which are mentioned in the first Mishnah.
The first Mishnah could have mentioned all of the Mitzvos mentioned in the second Mishnah, because all of those Mitzvos must be done after sunrise. Similarly, the second Mishnah could have mentioned all of the Mitzvos mentioned in the first Mishnah, because all of those Mitzvos may be done at any time during the day after sunrise. Why are these lists divided into two separate Mishnayos? (RASHBA in the name of RABEINU TAM; TUREI EVEN)
ANSWERS:
(a) The RASHBA and RITVA write that the first Mishnah lists only Mitzvos for which the requirement that they be performed after sunrise is novel. It is a Chidush that the morning reading of the Megilah may not begin until daybreak, because the other reading of the Megilah is done at night l'Chatchilah. It is a Chidush that Milah -- when performed she'Lo bi'Zemanah (on the ninth day or later) -- may not be done at night (indeed, Tana'im debate this issue). It is a Chidush that even the dipping of the Ezov into the water ("Tovlim," according to Tosfos and other Rishonim) may not be done at night, even though the sprinkling is done during the day. Shomeres Yom k'Neged Yom involves a Chidush, as the Gemara itself points out.
Why does the second Mishnah not list the Mitzvos that are mentioned in the first Mishnah? The RITVA explains that when the second Mishnah mentions "Korin ha'Megilah," the first Mitzvah of the list in the earlier Mishnah, it means "Korin ha'Megilah etc." -- that is, it refers to all of the other Mitzvos listed in the first Mishnah when it mentions the Mitzvah of Megilah.
(b) A simple answer may be suggested to explain why the Mitzvos mentioned in the first Mishnah do not appear in the second Mishnah's list of Mitzvos which "are done during the day and are valid the entire day." Of the first Mishnah's five Mitzvos -- Megilah, Milah, Tevilah, Haza'ah, and Tevilas Shomeres Yom k'Neged Yom -- four of them (with the exception of Megilah) are not actions performed specifically during the day! Although Milah may not be performed before sunrise of the eighth day, when Milah is performed she'Lo bi'Zemanah (on the ninth day or later) it may be performed at night (according some Tana'im). Similarly, Tevilah may be performed anytime after sunrise, even at night of the following day (RASHI DH v'Lo Tovlin), and the same applies to Tevilas Shomeres Yom k'Neged Yom. (Although Haza'ah indeed may never be performed at night, it is not mentioned in the Mishnah to teach the laws of Haza'ah but to disclose the source of the Halachah that Tevilah must wait until sunrise, as the Gemara explains.) It is clear why the Mishnah does not list these Mitzvos among the Mitzvos which "are performed during the day and are valid the entire day," as these Mitzvos are not considered Mitzvos "performed during the day." (-Based on the PNEI YEHOSHUA.)
(This answer, however, is valid only according to Rashi. According to Tosfos and the other Rishonim, the "Tevilah" of the first Mishnah refers to Tevilas Ezov, dipping the hyssop into the Mei Chatas, which may never be done at night. It certainly qualifies as a Mitzvah "performed during the day." Why, then, is it not mentioned in the second Mishnah? Similarly, according to the RASHBA and RITVA, when the first Mishnah says that Milah may be done only after sunrise, it refers to Milah she'Lo bi'Zemanah and it follows the Tana who permits the Mitzvah of Milah to be done only during the day. Accordingly, Milah should have been listed in the second Mishnah as well, since it certainly qualifies as a Mitzvah "performed during the day.")
This explains why the second Mishnah does not list all the Mitzvos which are mentioned in the first Mishnah (according to Rashi). The first Mishnah, however, could have included all of the Mitzvos mentioned in the second Mishnah, since all of those Mitzvos must be done only after sunrise. Why does it not include those Mitzvos? The answer is that the Tana found a more concise way to teach that all of the Mitzvos of the second Mishnah must be performed after sunrise: by simply listing one of those Mitzvos in the first Mishnah (the Mitzvah of Megilah) and repeating it in the second Mishnah, the Tana teaches that all the other cases in the second Mishnah may be compared to Megilah -- which is valid only from sunrise and on, as the first Mishnah says. The second Mishnah therefore has no need to mention the other Mitzvos listed in the first Mishnah.
Why does the Tana repeat specifically the Mitzvah of Megilah in both Mishnayos? The answer is that the Mitzvah of Megilah is the subject of the Maseches, and thus the Tana needs to be clear and explicit when discussing its laws (in contrast to the other laws which are mentioned in the Mishnah only as an aside). (-Based on the TUREI EVEN.)
(c) There is a basic difference between the laws taught by the two Mishnayos. The first Mishnah limits the time during which a Mitzvah may be performed and teaches that it may be performed only after sunrise and not earlier. The second Mishnah, in contrast, extends the amount of time during which a Mitzvah may be performed and teaches that it may be performed anytime during the day, and not just early in the day (Rashi DH Kol ha'Yom).
Perhaps each Mishnah lists only those cases which contain a Chidush. The first Mishnah lists only Mitzvos which may be performed for an extended period (they may be performed an any day), and nevertheless their time is limited somewhat (they may be performed only after sunrise). It lists Milah, Tevilah (either Tevilah of a person or of an Ezov), Haza'ah, and Tevilas Shomeres Yom, because all of these Mitzvos may be performed on any day after the required time passes, and they are not limited to a specific day. The Megilah, too, may be read on a number of days (as described in the Mishnah on 2a) and is not limited to one specific day. (Although each city or village may read the Megilah only on one specific day, the Mitzvah is considered to have an extended time in the sense that the Chachamim reserved five days for the performance of the same Mitzvah of Megilah.)
The second Mishnah, which extends the time allowed for the Mitzvah, lists only those Mitzvos which seem to have more limits to when they may be performed. The Mishnah teaches that they nevertheless are not limited to a specific time during the day but may be performed all day. The Mitzvos of Hallel, Shofar, Lulav, Musaf, etc., are limited to a specific day and may not be performed on any day one wants. For example, if one holds the Lulav only on one day of Sukos, he transgresses the positive Mitzvah to hold the Lulav for all of the other days of the festival; each day has its own Mitzvah which may not be done on any other day.
The Mitzvah of Megilah is included in the second Mishnah because it also has a time-limitation. Each specific city or village must read the Megilah on only one day of the year. One might have thought that its reading is limited to a specific time of the day as well. The Mishnah therefore teaches that it may be performed throughout the entire day. (M. Kornfeld)

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