Exodus 29:33-36

Verse 33

But a stranger shall not eat thereof - That is, no person who was not of the family of Aaron - no Israelite, and not even a Levite.
Verse 34

Burn the remainder with fire - Common, voluntary, and peace-offerings, might be eaten even on the second day; see Lev 7:16; Lev 19:5, Lev 19:6. But this being a peculiar consecration, in order to qualify a person to offer sacrifices for sin, like that great sacrifice, the paschal lamb, that typified the atonement made by Christ, none of it was to be left till the morning lest putrefaction should commence, which would be utterly improper in a sacrifice that was to make expiation for sin, and bring the soul into a state of holiness and perfection with God. See Clarke's note on Exo 12:10.
Verse 36

Thou shalt cleanse the altar - The altar was to be sanctified for seven days; and it is likely that on each day, previously to the consecration service, the altar was wiped clean, and the former day's ashes, etc., removed.
Copyright information for Clarke