"It is a tradition. The table [of the shewbread] was on the north side, distant from the wall two cubits and a half. The candlestick on the south, distant from the wall two cubits and a half. The altar [of incense] placed in the middle and drawn out a little towards the east."
So that the angel standing on the right side of the altar stood on the north side: on which side if there were an entrance into the Holy of Holies, as R. Chaninah thinks, then we may suppose the angel, by a sudden appearance, came out from the Holy of Holies.