Middos, Chapter 5, Mishnah 1. Having finished describing the individual structures of the Beit Hamikdash, the Mishnah now turns to the courtyard as a whole and gives us its overall dimensions. This mishnah takes the measurement from east to west and shows how the total is built up, section by section, out of everything we have already learned about.
The mishnah begins with the totals. The courtyard as a whole, "kol ha'azarah," had an "orech," a length, of "me'ah ushmonim vasheva": 187 amot. Its "rochav," its width, came to "me'ah ushloshim vachamesh": 135 amot. Both figures describe the space enclosed inside the Azarah, with the walls that ringed it left out of the reckoning.
The breakdown from east to west
"Min hamizrach lama'arav": travelling from the eastern end of the courtyard toward the west, that span of 187 amot is now broken down piece by piece.
First, upon entering from the east, came "mekom drisat Yisrael," a strip of "achad asar amah," eleven amot. Here the nation would gather, and ordinary Israelites, those who were not kohanim, did not normally proceed past it. Hence its name: the area upon which Yisrael was permitted to set foot.
Adjoining it was "mekom drisat hakohanim," a further "achad asar" amot set aside for the kohanim to stand and pass through, serving them chiefly as they came forward to bring the korbanot.
"Hamizbe'ach sheloshim ushtayim." The mizbe'ach itself occupied the following 32 amot of the courtyard's length.
"Bein ha'ulam velamizbe'ach": the gap running from the mizbe'ach's western edge up to the Ulam's front, eastern wall came to "esrim ushtayim amah," 22 amot, and it was within this stretch that the steps by which one ascended to the Ulam stood.
"Haheichal" took up "me'ah amah," a hundred amot, the figure for the Heichal along this axis that chapter four already supplied.
Last, "la'achorei beit hakapporet," behind the chamber that housed the kapporet, meaning behind the Kodesh Hakodashim at the western rear of the Heichal, there lay a further eleven amot, "achad asar amah."
Add the sections together: 11 for Yisrael, 11 for the kohanim, 32 for the mizbe'ach, 22 between the mizbe'ach and the Ulam, 100 for the Heichal, and 11 behind the Beit Hakapporet. The sum comes to exactly 187 amot, the full length of the Azarah from east to west.