- The Kohen Gadol’s first tevilah was on the שער המים
The Mishnah on Daf 30a taught, חמש טבילות ועשרה קדושין טובל כהן גדול ומקדש בו ביום – The Kohen Gadol performs five immersions and ten sanctifications, on the day of Yom Kippur, וכולן בקדש על בית הפרוה חוץ מזו בלבד – and all these tevilos are in the Kodesh, referring to the azarah, atop the Beis HaParvah, except for this first one only. The Gemara here, brings a Baraisa that teaches that the first tevilah was בחול, an unsanctified area, על גבי שער המים ובצד לשכתו היתה – atop the water gate, and it was located on the side of the Kohen Gadol’s lishkah. Even though the area under the gate had the kedushah of the azarah, the chamber above it that housed the mikveh did not, because the roofs of the azarah did not possess the kedushah of the azarah.
Abaye said we can deduce from here that Ein Eitam is a little more than twenty-three amos higher than the floor of the azarah. Rashi explains that Ein Eitam is a spring that supplied water via canals, to the mikveh used by the Kohen Gadol on Yom Kippur. We learned earlier that all the gates of the Temple, except for the ulam, were twenty amos high. Since the mikveh on top of the gate was three amos high, it must be that Ein Eitam was slightly more that twenty-three amos higher than the azarah floor.
- פרסו סדין של בוץ בינו לבין העם
The Mishnah stated, פרסו סדין של בוץ בינו לבין העם – They spread a linen sheet between the Kohen Gadol and the people, when he immersed. The Gemara asks what is unique about a sheet made of linen, and answers that it is in order שיכיר שעבודת היום בבגדי בוץ – so that the Kohen Gadol will realize that the special service of the day is performed with linen begadim.
- The Kohen washes once when putting on bigdei zahav for the first time
The next Mishnah states, פשט ירד וטבל – The Kohen Gadol undressed, descended into the mikveh, immersed, עלה ונסתפג – ascended and dried himself. They brought him the bigdei zahav and he put them on, וקידש ידיו ורגליו, and he sanctified his hands and his feet. A group of Rabbanon said in the presence of their Rebbe, Rav Pappa, that the Mishnah which does not require two sanctifications for the first immersion, does not go according to Rebbe Meir, since he said that the Kohen Gadol performs two sanctifications each time he puts on new begadim. Rav Pappa said that even Rebbe Meir would not require two washings here, since he learns a hekesh between פשיטה ולבישה – removing the garments and donning the garments. Just as the Kohen Gadol washes after he dons the new garments, so too he washes after he removes the used garments. The Rabbanon bring an explicit proof to Rav Pappa from a Baraisa, that Rebbe Meir holds that the Kohen Gadol does wash after he removes his bidgei chol, and then washes again when he dons the bigdei zahav for the first time, so our Mishnah is not like Rebbe Meir.
The Gemara goes on to clarify that according to the Rabbanon, who argue with Rebbe Meir and hold the Kohen Gadol only washed once when donning the bigdei zahav for the first time, the tenth washing was performed when he removed his bigdei zahav for the last time before he donned his bigdei chol.
