Yerushalmi: The Yerushalmi establishes this by the Tefilah of the Tzibur, but an individual who Davens, this is supplications (the way a person Davens with sincerity).

Explanation #1: Rashi explains that we silence him because it appears as if he is accepting two Masters.

Explanation #2: The and the Rach however, explain the opposite - that if he says it Pasuk by Pasuk, we do not silence him, even though it is disgusting.

Refutation: The wording of the Gemara however, does not imply their explanation (See Hagahos ve'Tziyunim & Tosfos Rebbi Yehudah).

Halachah #1: And as for those people who say the Pasuk 'Sh'ma Yisrael' twice on Yom Kipur, we silence them according to Rashi, whereas according to the Rach, at least it is disgusting.

Alternative: Perhaps the above only applies there where one reads the Sh'ma in its time, in order to accept upon oneself the yoke of Heaven (but not otherwise).

Conclusion: Nevertheless, it is preferable not to say it twice.

Halachah #2: But the custom to recite "Hash-m Hu ha'Elokim" seven times on Yos Kipur and on Hosha'na Rabah, corresponding to the seven Heavens, in praise of the Creator who dwells above them, is a good Minhag.

Proof: Indeed, we even find Hash-m Hu ha'Elokim" mentioned twice in a Pasuk in Melachim with regard to Eliyahu (on Har ha'Carmel).

Halachah: 'Batitu became silenced by 've'ha'Ofanim. When they came and asked Rebbi Bun, he cited Rebbi Yehoshua ben Levi that "Whoever replaced Batitu must resume where he left off.

Question: But did we not learn in our Mishnah that 'One must go back to the beginning of the B'rachah where the error occurred?

Answer: To which Rebbi Bun replied that since they had answered Kedushah, it was as it they were holding at the beginning of a B'rachah.

Question: Why is it not forbidden anyway, because answering 'Amen' in the middle of one's Tefilah is a Hefsek?

Answer: Seeing as the Gemara does not give this reason proves that answering 'Amen' is not considered a Hefsek, because it is necessary as part of Tefilah.

Answer (cont.): On the other hand, the Shatz is not permitted to call the Kohanim to Duchen, says Rabeinu Tam, since that is considered a Hefsek.

Conclusion: Consequently, somebody else should call them.

Implied Question: And when the Gemara in Perek Ein Ne'emarim (Sotah, 38.) says that 'When there are two Kohanim, one calls out 'Kohanim!' ...

Answer: It refers, not to the Shatz, but to the Chazan ...

Source #1: As we learned in the Sifri (Parshas Naso) "Say to them" teaches that the Chazan announces to them "Say!"

Clarification: And 'Chazan' is not the Shali'ach Tzibur, but rather (the Shamash) the one who is in charge of the communal issues.

Source #2: And this is also implied in Sotah (39:) - that it is not referring to the Shali'ach Tzibur, since first the Gemara there says that 'The Kohanim are not permitted to start the B'rachah until the word ('Kohanim) has terminated from the lips of the announcer, and it continues 'The Shali'ach Tzibur is not permitted ... '.

Conclusion: This implies that they (the announcer and the Shatz) are two different people.

Halachah: There are those who say that in similar vein, the Shatz is not permitted to call out to the Kohanim "Yevarech'cha" ... , since this too, is a Hefsek.

Alternative: Rabeinu Yehudah however, cites the Medrash Ta'amei Yeseiros va'Chaseiros specifically explains that from "Amor lahem" we learn that the Shali'ach Tzibur announces each word before the Kohanim.

Halachah: Likewise there are those who permit the Shatz himself to announce 'Kohanim', even according to Rabeinu Tam ...

Reason: Because when he referred to that as a Hefsek, that was specifically in those days, when they following the B'rachah of Hoda'ah, they did not say "Elokeinu v'Elokei Avoseinu Barcheinu ba'B'rachah ... '

Proof: As is implied in Sotah, where it says that 'The announcer is not permitted to call the Kohanim until 'Amen' has terminated from the lips of the Tzibur (with reference to the 'Amen' after the B'rachah of Hoda'ah.

Proof (cont.): This clearly implies that they immediately announced 'Kohanim' (and did not say 'Elokeinu v'Elokei Avoseinu ... ').

Conclusion: But nowadays, where it has become customary to first say 'Elokeinu ... ' in the form of a B'rachah and a Tefilah, it is not a Hefsek ...

Conclusion (cont.): As it is no worse than his answering 'Amen' in our Sugya, which is not considered a Hefsek, as we explained.

Explanation #1: Rashi explains that someone who remembers (in the middle of the Amidah) that he omitted a B'rachah, he inserts it there and then.

Refutation: This is not correct however, seeing as we learned in the second Perek of Megilah (Daf 17.) that 'Someone who reads the Megilah backwards (i.e. the chapters in the reverse order) is not Yotzei', And the Beraisa there adds that 'The same applies to Hallel, to K'ri'as Sh'ma and the Amidah'.

Explanation #2: The explanation of the Rashbam and the Rif, who interpret 'Ein lahem Seider' to mean that one goes back to the place where he skipped the B'rachah and continues from there follows the order of the B'rachos, is the correct one.

Conclusion: But for sure, one does not need to begin again from 'Atah Chonein', in the way that one does by the first and the last three B'rachos.

Proof #1: Proof for this, lies in the Tosefta of this Masechta, which states that 'Someone who reads the Sh'ma, and omits one Pasuk, should not subsequently recite that Pasuk on its own, but should rather begin from that Pasuk, and continue from there till the end.

) Proof #2: And we also learned in the second Perek of Megilah (Daf 18:) that if one slipped a Pasuk in the Megilah, one reads in order from the Pasuk that he skipped; And the Gemara there equates Tefilah with Megilah in this regard, as Tosfos just explained.

Halachah: The B'hag rules like Rav Asi, who says that 'The middle B'rachos do not have a Seider' ...

Proof #1: Firstly, because Rav Huna is considered a Talmid vis-a-vis Rav Asi, as we find in a number of places, where Rav Huna quotes Rav Asi.

Proof #2: Secondly, because Rav Huna needs to give a 'forced' answer (Dochek), when he explains our Mishnah by saying that all the (middle) B'rachos are one B'rachah'; and we tend not to rely on forced answers.

Proof #3: Thirdly, because Rav Asi and Rav Sheishes share one opinion.

Proof #4: Fourthly, because in matters that are de'Rabbanan, we follow the lenient opinion.

Conclusion: As a result, someone who erred and skipped one of the middle B'achos, or who failed to insert 'ha'Melech ha'Mishpat' betwen Rosh ha'Shanah and Yom Kipur (for which, the Gemara in the first Perek (Daf 12:) rules, one must go back), one does not go back to 'Atah Chonein', but to the B'rachah from which he skipped, and continue from there, like the opinion of the Rashbam.

Halachah: And if one erred in the first three B'rachos, where, for example, one erred with regard to the conclusion of the B'rachah, or where one failed to mention 'Zachreinu' in Avos, 'Mi Chamocha' in Techi'as ha'Meisim or 'ha'Melech ha'Kadosh' ... , one goes back to the beginning.

Halachah (cont.): And if one erred in the last three B'rachos, such as where one likewise erred at the conclusion of the B'rachah, or where, between Rosh ha'Shanah and Yom Kipur, one failed to mention 'be'Seifer Chayim' in 'Sim Shalom', or 'u'Chesov le'Chayim Tivim' in Hoda'ah, one goes back to Avodah (i.e. Retzei).

Reason: Because, since it is all praise (of Hash-m), it is considered one B'rachah.

Halachah: On a Ta'anis, where the Shatz recites an independent B'rachah - when he says 'Aneinu' between 'Go'el' and 'Rofei', in the event that he forgot it, and remembered before the conclusion of the Amidah, he does not say it ...

Reason: Seeing as this would entail going back and reciting the Amidah in order (according to the Rashbam), which in turn, would mean reciting a B'rachah Levatalah.

Alternative: Whereas according to Rashi, he would recite it there and then, without involving a B'rachah Levatalah.

Clarification: Rabeinu Chananel explains that this speaks exclusively about praying for one's individual needs. Praying for communal needs is permitted.

Consequently: That explains why we say 'Zochreinu', 'K'rovotz' (i.e. Piyutim) and 'Ya'aleh ve'Yavo' in those B'rachos.

Proof: AS proof that the Gemara is confined to individual Tefilos, the main thrust of the last three B'rachos comprises communal needs.

Question: So what if he bows down?

Answer #1: The reason is to prevent him from negating the words of the Chachamim, that people should not say that every Tom, Dick and Harry may take on any stringency that he pleases, and that in the end, there will be no Takanas Chachamim.

Answer #2: Moreover, we are concerned with presumptuousness (pride).

Proof: And the Gemara cites a Pasuk.

Implied Question: Even though there is another explanation (See Tosfos Ha'Rosh).

Answer: The Gemara relies on the tradition that it had that 'Kidah' means on the face, and cites the Pasuk accordingly.

Clarification: This means that they turned on their sides.

Implied Question: What the Gemara says earlier in Tefilas ha'Shachar (Daf 30:) that (before a person Davens) 'He should assess as to whether he can concentrate (in which case he should Daven), or not (in which case, he shouldn't) ...

Answer: It too, is referring to one B'rachah.

Question: But does the Torah not write that "Yitzchak went to Daven in the field"?

Answer #1: That refers to Har ha'Moriyah, as the Gemara says in Pesachim in Perek ha'Ishah (Daf 88.) 'Not like Yitzchak, who called it a field.

Answer #2: Alternatively, the valley that our Sugya mentions refers specifically to a location which is frequented by many people and travelers.

Reason: Because that is a sign that a person is ashamed of his sins.

Reason (cont.):: Whereas publicizing them, indicates that he is not embarrassed.

Source: And we learned above in the first Perek (Daf 12:) that "Whoever is ashamed of something wrong that he has done, receives a pardon for all his sins