Mizbeach HaChitzon

The outer altar, built of stones untouched by iron, joined with plaster and whitewashed with lime twice a year. Its base, the yessod, is 32 amot on each side and one ama high; a one-ama setback gives 30 × 30 up to the sovev, the walkable ledge at six amot; a second setback gives 28 × 28 up to the surface of the fire. Four hollow horns, one ama by one ama, occupy the corners. It is not centered on the axis of the Heikhal: it is offset nine amot to the south.

Dimensions

• yessod: 32 × 32 amot, 1 ama high
• 30 × 30 up to the sovev, at 6 amot high (1 yessod + 5)
• 28 × 28 up to the surface (ma'arakha)
• keranot: four hollow horns, one ama by one ama, at the corners; one ama high in the model, five tefachim according to the Rambam (Beit HaBe'hira 2:8)
• 1 ama of walkway (makom hilukh haregel), then a 24 × 24 fire zone
• total height 10 amot (≈ 4.8 m) in the model: 9 to the surface + 1 for the horn (choice of the tour); according to the Rambam, 58 tefachim in all, of which 9 amot less one tefach up to the ma'arakha (Beit HaBe'hira 2:6, 2:9)
• 32 amot in both the east-west and north-south division of the Azara
• north edge at 60.5 amot from the north wall: center 9 amot south of the axis of the Heikhal

Sources

• Middot 3:1
• Middot 3:4
• Middot 5:2
• Rambam, Hilchot Beit HaBechirah 2:6“וְגֹבַהּ כָּל הַמִּזְבֵּחַ נ"ח טְפָחִים”
• Rambam, Hilchot Beit HaBechirah 2:7“עָלָה חֲמִשָּׁה טְפָחִים וְכָנַס חֲמִשָּׁה טְפָחִים זֶהוּ יְסוֹד”
• Rambam, Hilchot Beit HaBechirah 2:8“גֹּבַהּ כָּל קֶרֶן וְקֶרֶן חֲמִשָּׁה טְפָחִים. וְרִבּוּעַ כָּל קֶרֶן אַמָּה עַל אַמָּה”
• Rambam, Hilchot Beit HaBechirah 2:9“וְנִמְצָא גָּבְהוֹ מִן הָאָרֶץ עַד מְקוֹם הַמַּעֲרָכָה תֵּשַׁע אַמּוֹת פָּחוֹת טֶפַח”
• Rambam, Hilchot Beit HaBechirah 5:15“מכותל צפוני של עזרה עד כותל המזבח שהוא רוחב ששים ומחצה”
• Zevachim 58b“מִשּׁוּם דְּרַבִּי יְהוּדָה שְׁמַעְנָא לֵיהּ מְמוּצָּע בְּהֶדְיָא”
• Zevachim 59a“צפונה”

Project decisionAdopted: the altar shifted to the south, its center nine amot south of the axis of the Heikhal. This is what the measurements of Middot 5:2 give as the Rambam reads them, and the view of R. Eliezer ben Yaakov, who wants the “north” — where the most holy offerings are slaughtered — free of everything, even of the altar (Zevachim 59a). Set aside: R. Yehuda's altar centered in front of the Heikhal (Zevachim 58b), which many models follow, and R. Yosei HaGelili's altar lying entirely in the north (Zevachim 59a). The round figures are those of the first opinion in Middot 3:1, where R. Yosei describes an original altar of 28 × 28 that the returning exiles enlarged by four amot to the south and west; the Rambam counts in tefachim (Beit HaBe'hira 2:7): a yessod of five tefachim, a surface of 28 amot and four tefachim, a ma'arakha of 24 amot and four tefachim. Choice of the tour: the height of ten amot, as nine to the surface plus one for the horn, which the Rambam does not give in this way.