Oecumenius

Then the divine angel took the censer, filled it with the fire of God, and threw it to the earth; and there were voices, sounds of thunder, lightning flashes, and an earthquake. Perhaps one of the angels cast this divine fire upon Mount Sinai, and there were sounds of thunder, voices, trumpets, flashes of lightning, and the mountain was covered with smoke as God descended upon it. Just as then the thunder and the signs preceded, so now these things have preceded the glorious coming of the Lord.

Commentary on Revelation ↗

Bede

And there were thunders, and voices, and lightnings, and an earthquake. With the thunder of divine threat, and the voice of exhortation, and the lightning of miracles, He moved the earth, some following, others preceding, these saying: "He is good," but others: "No, but he deceives the people" (John 7).

Commentary on Revelation ↗

Alcuin of York

And the angel took the censer, and filled it with the fire of the altar, and cast it on the earth. The angel took the censer when the Lord joined human nature to himself within the Virgin's womb; or we may take it as referring to the body, when he first chose his disciples in Judea. …

Commentary On Revelation ↗