Angels are involved in miracles, live in heaven and have a measure of greatness

Psalm 78:25 Human beings ate the bread of angels;* he sent them all the food they could eat.
We know that there was something supernatural about the manna that the Children of Israel ate in the wilderness. It fell daily from heaven just where the people were. It had variable properties that made it rot if kept overnight except on the night before the Sabbath. Asaph here calls it the bread of angels. Now why does he call it that? Certainly, angels are spiritual beings and have no need of food. The Puritan Arthur Jackson makes three suggestions as to what Asaph may have in mind
  1. Because it was provided and sent by the ministry of angels
  2. Because it seemed to come down from heaven, the dwelling place of the angels
  3. To set forth the excellency of this bread, that it was meat, as one would say, fit for angels, if angels needed meat.
Coming at the matter from the other end then, we remind ourselves that God delights to do his miracles through the agency of angels and that heaven is their home, there in the presence of God. They are also a useful benchmark for excellence or greatness.
* The Hebrew has mighty ones but the LXX legitimately has angels