Bonaventure — on Rev 7:2 (Collations on the Hexaemeron, Collation 16)

“The day of the formation of man, the time of the prophetical voice, and the time of the clear doctrine, in which the prophesized life would come: for it was necessary that in this time there come a single order, that is, a prophetical disposition similar to the order of Jesus Christ, and of which the head would be an "angel ascending from the rising of the sun, having the seal of the living God," and conforming to Christ.”