“And Moses and Aaron went into the tent of meeting, and came out, and blessed the people; and the glory of the L-RD appeared unto all the people. And there came forth fire from the L-RD.” – Leviticus 9:23, JPS 1917 Tanach
“The fire came down like a pillar from heaven to earth.” – Sifra
The people had grown expectant, to the point of concern, over the previous seven days, in which Moses daily performed the inauguration service on his own. On the eighth day, corresponding to the first of Nissan, one year after leaving Egypt, everything was in place; yet, still there was no fire from Shomayim (Heaven).
The offerings of that day included a calf as a sin-offering, of which commentary mentions atoned for Aaron’s role in the making of the golden calf. Also, a goat as a sin-offering to atone for the people. Additionally, an olah, and the people’s shelamin – peace offering – as well as the daily morning Tamid offering.
It was at this point, that “Moses and Aaron went into the tent of meeting.” One possible explanation, offered by Rashi, who refers to Sifre, is that when Aaron perceived that the offerings had been made, yet, the heavenly fire had not descended, he thought that H’Shem was still angry with him, because of his role in the sin of the golden calf. He pleaded to Moshe, in the midst of his “inner shame,” whereupon they both entered the sanctuary to pray for H’Shem’s mercy.
What can be learned from this event? Even upon beginning his role as Kohein Gadol, when making the first offerings, Aaron recalled his sin, and through the prayers of Moshe, sought complete atonement and forgiveness for his role in the making of the golden calf. Overall, this must have been a humbling experience for him; elsewhere, commentary explains that even though he felt ashamed, this was precisely why he had been chosen, because he remained humble, as a result of recalling his sin. The principle is encapsulated in the pasuk (verse), “my sin is ever before me” (Psalm 51:5). If we keep our past sins in mind, this will help us to keep our ego in check.