John the Apostle
Revelation 21:9BSB·traditional attribution

Then one of the seven angels with the seven bowls full of the seven final plagues came and said to me, “Come, I will show you the bride, the wife of the Lamb.”

Matthew Henry Presbyterian @wholebiblehenry

We have already considered the introduction to the vision of the new Jerusalem in a more general idea of the heavenly state; we now come to the vision itself, where observe, I. The person that opened the vision to the apostle - one of the seven angels, that had the seven vials full of the seven last plagues, Rev 21:9.

Commenting on Revelation 21:9-27

John Gill Reformed Baptist @doctorgill

And there came unto me one of the seven angels,.... Either the first of them, as one of the four beasts is the first of them, Rev 6:1 or it may be the last, and very likely the same as in Rev 17:1 which had the seven vials full of the seven last plagues; that is, the wrath of God poured out by them on...

Albert Barnes Presbyterian @notesbybarnes

Verse 9. And there came unto me one of the seven angels, etc. . Why one of these angels was employed to make this communication is not stated. It may be that as they had been engaged in bringing destruction on the enemies of the church, and securing its final triumph, there was a propriety that that triumph should be announced by one of their number. And talked with me.