1) "SHEM HA'MEFORASH" -- THE INEFFABLE NAME OF G-D
OPINIONS: The Gemara teaches that when the Kohen Gadol recited Viduy on Yom Kippur, he uttered the Name of Hash-m. The requirement to utter the Name of Hash-m is derived from the procedure of the Eglah Arufah, for which the verse says that the Name of Hash-m is used in the request for atonement (Devarim 21:8).
When the Mishnah quotes the words of the Viduy which the Kohen Gadol recited, it does not refer to the Name of Hash-m in the usual manner. Normally, the Mishnah refers to the Name with an abbreviation, the letter "Dalet." This Mishnah, though, relates that the Kohen Gadol said "ha'Shem" (Heh, Shin, Mem). The reason for this change is that the Name uttered on Yom Kippur by the Kohen Gadol was not the normal Name of Hash-m. On Yom Kippur, the Kohen Gadol used the Shem ha'Meforash, the "ineffable Name." When the Kohen Gadol uttered the ineffable Name, everyone who heard the Name bowed down (66a). The Gemara (39b) says that the Kohen Gadol uttered the Shem ha'Meforash ten times on Yom Kippur: three times in each of the three Viduyim, and one time when he selected the Sa'ir of Hash-m.
What exactly is the Shem ha'Meforash that the Kohen Gadol used on Yom Kippur?
(a) The ROSH (in AVODAS YOM KIPPUR, and in TOSFOS HA'ROSH to 39b, and as cited by the TUR OC 621) writes that the Kohen Gadol uttered the four-letter Name of Hash-m (the Tetragrammaton) and pronounced it as it is written (k'Kesivaso). He did not utter any of the other Names of Hash-m, such as the 42-letter Name. The Rosh proves this from the Gemara here which derives the requirement for the Kohen Gadol to say the Name of Hash-m from the procedure of Eglah Arufah, for which the verse mentions the four-letter Name of Hash-m. The Name which the Kohen Gadol used also must be the four-letter Name of Hash-m.
This is also the opinion of the RAMBAM (Hilchos Avodas Yom ha'Kipurim 2:6).
(b) RAV HAI GA'ON (cited by the Tur) argues and says that the Kohen Gadol used the 42-letter Name of Hash-m and not the four-letter Name of Yud and Heh. This appears to be the opinion of the TOSFOS YESHANIM (39b) as well.
The Rishonim adduce a number of proofs for the opinion of Rav Hai Ga'on, who says that the Name used by the Kohen Gadol on Yom Kippur was the 42-letter ineffable Name of Hash-m:
1. The Gemara says that the Kohen Gadol mentioned the Name of Hash-m ten times on Yom Kippur. The TOSFOS RID (70a) asks that the Gemara in Sotah (38a) says that the Kohanim recited Birkas Kohanim in the Beis ha'Mikdash with the Name of Hash-m as it is written. Since the Kohen Gadol also recited Birkas Kohanim on Yom Kippur, he uttered the Name of Hash-m more than ten times.
This is a question only on the Rosh, who maintains that the Kohen Gadol uttered the four-letter Name of Hash-m. This is not a question according to Rav Hai Ga'on, who maintains that the Kohen Gadol uttered the 42-letter Name of Hash-m each of those ten times. During Birkas Kohanim, the Kohen Gadol used only the four-letter Name.
2. The TOSFOS RID asks further that the Gemara (Yoma 68b) teaches that the Kohen Gadol blessed the people with eight blessings after he completed the Avodah on Yom Kippur. In those blessings, he apparently used the Shem ha'Meforash as well. The Gemara in Berachos (63a) says that the people never said "Amen" in the Beis ha'Mikdash at the end of a blessing. Rather, they said, "Baruch Shem Kevod Malchuso...." The reason they said "Baruch Shem" instead of "Amen" is presumably because the public blessings in the Beis ha'Mikdash were said with the Shem ha'Meforash, to which the proper response is "Baruch Shem" as the Mishnah here says (RITVA in Ta'anis 16a, TZELACH in Berachos 63a, MAHARSHA in Sotah 41a).
Since the Gemara says that the people responded to "all" public blessings in the Mikdash with "Baruch Shem," it must be that these eight blessings recited by the Kohen Gadol on Yom Kippur were also said with the Shem ha'Meforash. This is problematic according to the Rosh, who says that the Shem ha'Meforash is the four-letter Name, because the Kohen Gadol used the Shem ha'Meforash far more than ten times. It must be that the Kohen Gadol used the 42-letter Name ten times (as Rav Hai Ga'on maintains), while for all other blessings he used the four-letter Name.
3. The GEVURAS ARI (66a) points out that the Mishnah says that all the people who heard the Shem ha'Meforash bowed down. However, the Mishnah does not say that they also bowed down during Birkas Kohanim, even though the Kohanim uttered the Name of Hash-m as it is written (Sotah 38a). It must be that the Name for which they bowed was the 42-letter Name, while the Name used in Birkas Kohanim was the four-letter Name.
How does the Rosh, who says that the Kohen Gadol uttered the four-letter Name of Hash-m on Yom Kippur, understand these strong proofs against his opinion?
1. The TOSFOS RID answers that there was no obligation for the Kohen Gadol himself to participate in the Birkas Kohanim on Yom Kippur. Other Kohanim may have performed the Birkas Kohanim, and thus the Kohen Gadol himself did not recite the Name of Hash-m an additional time.
The MIKDASH DAVID (24:2) answers that perhaps when the Gemara says that the Kohen Gadol uttered the Name of Hash-m ten times, it refers to the era after Shimon ha'Tzadik. The Gemara (39b) says that after Shimon ha'Tzadik passed away, the Kohanim stopped saying the Birkas Kohanim with the Name of Hash-m. (The Tosfos Rid, who does not suggest this answer, follows his own opinion on 39b that even after Shimon ha'Tzadik passed away the Kohanim said the four-letter Name (as it is written) in Birkas Kohanim.)
2. RASHI (69b, DH b'Gevulin) writes that the Shem ha'Meforash was not used for blessings except for those recited in the Azarah itself. It was not used anywhere else on Har ha'Bayis. The eight blessings said by the Kohen Gadol after the Avodah of Yom Kippur were said in the Ezras Nashim (Yoma 69b) which did not have the sanctity of the Azarah, and thus those blessings were not said with the Shem ha'Meforash, the four-letter Name of Hash-m as it is written.
The RASHASH points out that the people in the Ezras Nashim certainly did not answer "Amen" to the blessings, but they answered "Baruch Shem" as the Gemara (69b) says. Why did the people say "Baruch Shem" even when the Shem ha'Meforash was not used?
The CHONEN DE'AH (Rav Nechemya Friedlander of Bnei Brak) explains that perhaps this point is the basis of a dispute among the Rishonim here. RASHI says that the eight blessings were recited without the Shem ha'Meforash, and yet the people still answered "Baruch Shem." Rashi maintains that the response "Baruch Shem" does not depend on the Shem ha'Meforash; "Baruch Shem" may be said even when the Shem ha'Meforash is not said. Rashi's opinion explains how it was that the people responded "Baruch Shem" to all of the blessings, even though the Kohen Gadol said the Shem ha'Meforash only ten times. The other Rishonim, who maintain that the Name used by the Kohen Gadol in the Viduy was the 42-letter Name, maintain that the Kohen Gadol did say the four-letter Name in the eight blessings in the Ezras Nashim, and that is why the people answered "Baruch Shem." Accordingly, the argument whether the Shem ha'Meforash was said in the Ezras Nashim, and whether "Baruch Shem" may be said even when the Shem ha'Meforash is not, depends on whether the Kohen Gadol uttered the 42-letter Name or the four-letter Name in the Viduyim.
The RITVA (39a-b), however, maintains that the Kohen Gadol used the four-letter Name of Hash-m during the Viduyim, even though he also maintains that the Kohen Gadol used the four-letter name as it is written wherever "Baruch Shem" was said, even in the Ezras Nashim (Ritva to Ta'anis 16a). According to the Ritva, why does the Gemara say that the Shem ha'Meforash was uttered on Yom Kippur only ten times?
The RITVA himself (in Berachos 63a) and the RASHBA (ibid.) quote the RA'AVAD, who asserts that neither the Shem ha'Meforash nor "Baruch Shem" were said except in the prayers in the Beis ha'Mikdash. When the Kohen Gadol recited a blessing over the reading of the Torah, the normal Shem Hash-m was used. Perhaps the eight blessings of the Kohen Gadol, which were recited after he read from the Torah, were also not considered part of the prayers and thus did not require the Shem ha'Meforash.
3. Perhaps the reason why the people did not bow down during Birkas Kohanim was not because the Kohanim did not use the Shem ha'Meforash, but because the blessing of Birkas Kohanim must be done "face to face" -- "Panim k'Neged Panim" (Sotah 38a). The people needed to face the Kohanim during Birkas Kohanim and thus they could not bow down. In contrast, when the Kohen Gadol said the Viduy he was not blessing the people, so they could bow down when he said the Shem ha'Meforash.
It should be noted that according to TOSFOS in Sotah (38b), the people did bow down during Birkas Kohanim. Moreover, the VILNA GA'ON emends the text of the Mishnah (66a) based on the text as it appears in the Yerushalmi, such that it makes no mention of bowing down on Yom Kippur (just as the earlier Mishnayos (35b, 41b) make no mention of bowing when the Shem Hash-m was said). According to his Girsa, no proof may be adduced from the wording of the Mishnah. (See Insights to Yoma 66:1.)