1) RECITING VERSES FROM THE TORAH BY HEART
QUESTION: The Mishnah states that during Shacharis the Ma'amados read from the Sefer Torah, and during the other Tefilos of the day they read the Parshiyos by heart "like those who read the Shema."
What does the Mishnah intend to add by saying that the Parshiyos are read like the Shema?
ANSWER: The Gemara in Gitin (60b) rules that a verse in the Torah may not be read by heart. Why, then, are the Ma'amados permitted to read verses from the Torah by heart? The Mishnah addresses this question when it adds that they read the verses by heart "like those who read the Shema." The Mishnah means that the same way one is permitted to read the Shema by heart, the Ma'amados are permitted to read the Parshiyos by heart. Reading the Shema by heart is permitted because it is incumbent upon every Jew to read the Shema twice each day, and not every Jew has a Sidur from which to read it. The Mishnah says that just as one is permitted to recite the Shema by heart, the Ma'amados are permitted to read the Parshiyos by heart.
Why, though, is one permitted to recite the Shema by heart, if the Gemara in Gitin rules that verses in the Torah may not be said by heart?
(a) The RITVA in Yoma (70a) explains, based on the Yerushalmi, that the prohibition against reading verses of the Torah by heart applies only to verses which must be read publicly ("Chovas Keri'as Tzibur"). The prohibition does not apply to verses read for the sake of reviewing the Torah, or for the sake of giving praise to Hash-m.
In the case of the Mishnah here, the obligation for the Ma'amados to read from the Torah publicly applies only during Shacharis. During the rest of the day, there is no obligation to read from the Torah, and therefore they may recite the verses by heart. Similarly, there is no obligation to read the Shema publicly, and therefore it may be recited by heart.
TOSFOS in Temurah (14b, DH Devarim) also suggests that one is prohibited to recite verses by heart only when he recites them on behalf of the public (to enable them to fulfill their obligation). In the case of Keri'as Shema and the reading of the Ma'amados, no individual reads on behalf of the public.
(b) The TALMIDEI RABEINU YONAH in Berachos (9b) cite RABEINU SHLOMO MIN HA'HAR, who asks a similar question on the Gemara in Berachos. He explains that the Torah requires an individual to read certain verses, but it does not require him to read them from a Sefer Torah. For example, the Torah requires one to recite the Shema twice each day, but it permits him to recite the verses of Shema by heart. The Torah does not expect every person to read the Shema twice each day from a Sefer Torah. The same applies to the verses of Birkas Kohanim which the Kohanim recite each day when they bless the people. Similarly, in the case of the Gemara here, when the Torah requires the members of the Ma'amados to recite these verses, it does not require that they recite them from a Sefer Torah.
(c) The TUR (OC 49) quotes his uncle, RABEINU CHAIM, who says that one is permitted to recite by heart verses in which he is fluent, because there is no concern that he might err. This may explain why the Shema and the verses recited by the Ma'amados may be said by heart.
(d) The SHILTEI GIBORIM in Megilah (14a of the pages of the Rif) rules that it is permissible for the congregation as a whole to recite verses by heart. This would apply to Shema and the verses said by the Ma'amados as well. Apparently, his reasoning is the same as that of the Tur: since there is no concern that the entire congregation will err, they are permitted to recite the verses by heart.
2) HALACHAH: BIRKAS KOHANIM DURING MINCHAH ON A TA'ANIS
OPINIONS: The Gemara records different opinions among the Tana'im whether Birkas Kohanim is recited during Minchah on a Ta'anis (see Chart). Which opinion does the Halachah follow?
The Gemara concludes that the Halachah follows the view of Rebbi Yosi who says that Birkas Kohanim is not recited during Minchah on a Ta'anis, but only during Shacharis, Musaf, and Ne'ilah. His reason is because Minchah on all other days is recited at a time when people are still under the influence of the intoxicating beverages they consumed during the afternoon meal, and a Kohen is forbidden to bless the people after he has consumed an intoxicating beverage. If the Kohanim would be permitted to recite Birkas Kohanim during Minchah on a Ta'anis, they might recite it on an ordinary day as well, after they have consumed wine. However, when Minchah on a Ta'anis is recited late in the day (just before sunset), Birkas Kohanim is recited; in that case, Minchah is like Tefilas Ne'ilah which has no parallel on an ordinary day.
The Rishonim give different interpretations for this "compromise."
(a) According to the RAMBAN, the Gemara maintains that the Kohanim may recite Birkas Kohanim during Minchah on a Ta'anis even when Minchah is recited early in the afternoon, as Rebbi Meir rules. However, the Gemara rules as a stringency that the Kohanim should not recite it unless Minchah is recited towards the end of the day.
(b) Other Rishonim understand the Gemara in the opposite way: the Gemara maintains that the Kohanim may not recite Birkas Kohanim during Minchah, as Rebbi Yosi rules. However, on a Ta'anis in which Ne'ilah is not recited (such as the five fast days observed for the destruction of the Beis ha'Mikdash), Birkas Kohanim is recited because Minchah takes the place of Ne'ilah on such a day.
HALACHAH: The Gemara's conclusion implies that whether or not Birkas Kohanim is recited during Minchah on a Ta'anis depends on when in the day Minchah is recited. When Minchah is recited early in the afternoon, Birkas Kohanim is not recited. When Minchah is recited late in the afternoon, it takes the place of Ne'ilah and Birkas Kohanim is recited.
However, the CHAZON ISH (OC 20) suggests that perhaps Birkas Kohanim does not depend on when Minchah is recited. Rather, since the practice during the times of the Gemara was to recite Minchah late in the afternoon, the Chachamim instituted that Birkas Kohanim is recited during Minchah of a Ta'anis regardless of when Minchah is recited. (This explains the practice followed by some congregations to recite Birkas Kohanim during Minchah on a Ta'anis even when Minchah is recited early in the afternoon.)
After sunset, Birkas Kohanim is not recited (as the Yerushalmi here says). Therefore, if the Chazan's repetition of the Minchah Shemoneh Esreh extends past sunset, Birkas Kohanim is not recited. The same applies for Ne'ilah. (See MISHNAH BERURAH OC 129:1.)
Even though Birkas Kohanim is not said during Minchah when Minchah is recited early in the afternoon, if a Kohen mistakenly goes up to say Birkas Kohanim he is not sent down and he may say Birkas Kohanim. Also, the common practice is for the Chazan to recite the verses of Birkas Kohanim during Minchah on a Ta'anis when the actual Birkas Kohanim is not performed.