Sukkah, Chapter 4, Mishnah 5. In the previous section we learned that there was a mitzvah to bring the aravah (willow branch) to the Beis Hamikdash on each day of the festival. Now the Mishnah goes on to describe how this mitzvah was actually carried out.
"Mitzvas aravah keitzad": - How was the mitzvah of the aravah performed?
"Makom hayah l'matah miYerushalayim v'nikra Motza" - There was a place below Jerusalem called Motza. Jerusalem is built on a mountain, and below that mountain was a place called Motza. This place still exists today, near the entrance to Jerusalem, and many willows still grow there.
"Yordin l'sham v'lokitin misham morbiyos shel aravah" - They would go down to that place and cut large willow branches there. "U'va'in v'zokfin osan b'tzidei hamizbe'ach" - They would bring them and stand them up alongside the Altar in the Beis Hamikdash. The willows were eleven amos tall, while the Altar was only ten amos high, and therefore "rasheihen kefufin al gabei hamizbe'ach" - the tops of the willows would bend and hang over the top of the Altar.
"Taku v'heri'u v'saku" - As the willows were brought in, they would sound a tekiah, a teruah and a tekiah on the trumpets of the Beis Hamikdash.
The Circuits Around the Altar:
The Mishnah continues: on each day of Sukkos they would circle the Altar one time. In the Gemara the Amoraim disagree about how this circuit was made: some say they would circle the Altar holding the willows and only afterward stand them alongside the Altar, and others say that they would first stand the willows alongside the Altar, and make the circuit holding their lulavim.
During the circuit they would recite the verses from Tehillim: "Ana Hashem hoshi'ah na, ana Hashem hatzlichah na" - Please, Hashem, save us; please, Hashem, grant us success. Rabbi Yehudah cites a slightly different version, familiar to us from the Hoshanos: "Ani vaho hoshi'ah na" - "I and He," as if to say that the Holy One, Blessed is He, joins with us in this request.
Hoshana Rabbah:
The Mishnah does not specify which day it is referring to, but it means the seventh day of the festival - Hoshana Rabbah. On that day they would circle the Altar seven times, just as we do today on Hoshana Rabbah.
When They Took Leave of the Altar:
As they departed from the Altar, at the conclusion of the circuits, what would they say? They would say twice: "Yofi lach mizbe'ach" - Beauty is yours, Altar. This beauty that we perform for your sake, Altar, is only because you provide us with atonement.
Rabbi Eliezer cites a slightly different version: "Lecha ul'mizbe'ach" - To You and to the Altar. The Gemara raises a difficulty with this, since one may not associate Hashem's Name together with anything else such as the Altar, and it explains that this is what they meant: to You, Hashem, we give thanks; and to you, Altar, we give praise for your ability to provide atonement.
In summary: In this Mishnah we learned the order of the mitzvah of the aravah in the Beis Hamikdash - the gathering of the willows at a place called Motza below Jerusalem, standing them alongside the Altar with their tops bending over it, the trumpet blasts that accompanied this, the circuit around the Altar once each day and seven times on Hoshana Rabbah, the text recited during the circuit, and the words said upon taking leave of the Altar.