Gregory of Nyssa, on Ps 102:20

“Bless the Lord, all ye his angels: you that are mighty in strength, and execute his word, hearkening to the voice of his orders.”

“Under "thrones" [Paul] includes the cherubim, giving them this Greek name, as more intelligible than the Hebrew name for them. He knew that "God sits upon the cherubim," and so he calls these powers the thrones of him who sits on them. In the same way there are included in the list of Isaiah's seraphim, by whom the mystery of the Trinity was clearly proclaimed, when they uttered that marvelous cry "holy," being awestruck with the beauty in each person of the Trinity. They are named under the title of "powers" both by the great Paul and by the prophet David—the latter says, "Bless you the Lord all you his powers, you ministers of his that do his pleasure," and Isaiah instead of saying "Bless you" has written the very words of their blessing, "Holy, holy, holy, Lord God of hosts: the whole earth is full of his glory," and he has revealed by what one of the seraphim did [to him] that these powers are ministers that do God's pleasure, effecting the "purging of sin" according to the will of him who sent them: for this is the ministry of these spiritual beings, namely, to be sent forth for the salvation of those who are being saved.”

Imported from an open dataset — not yet checked against the printed edition.