Which THREE prophets returned from Babylon and each attested to a different aspect of the Altar's validity?
Chaggai attested to the site, Zechariah to its dimensions, and Malachi permitted all sacrifices to be offered there even before the Temple was rebuilt (Halachah 4, from Zevachim 62a).
Question 2
Why was the Altar's base absent at the southeast corner?
The Temple Mount was mostly in Judah's territory, but the Altar was to stand entirely in Benjamin's inheritance. A small strip of Judah's land intruded into that space, so the southeast corner's base was omitted (Halachah 10).
Question 3
What was the purpose of the scarlet band girded around the middle of the Altar?
The scarlet band divided the Altar into upper and lower zones, separating the blood of birds brought as burnt offerings (cast above) from the blood of sin offerings and animals (sprinkled below) (Halachah 9).
Question 4
Which four elements are absolute requirements for a valid Altar?
Halachah 17 states that horns, base, ramp, and square shape are indispensable — the Torah uses the definite form 'the Altar' in connection with each one, implying that without any of them, the structure is not called an Altar at all.
Question 5
Why was there a small gap between the ramp and the Altar surface, requiring priests to toss sacrificial limbs rather than place them directly?
Zevachim 62b derives from Deuteronomy 12:27 that flesh and blood are compared — blood must be tossed (Leviticus 1:5), so the limbs must also reach the pyre by being tossed, not placed (Halachah 13).