Oecumenius — on Rev 4:5 (Commentary on Revelation)

“The flashes of lightning and the sounds of thunder emanating from the throne once again signify the awe-inspiring presence of God. For divine beauty does not lie in some long-winded pleasure or delight, but in a wondrous and awe-inspiring reverence. And knowing this, the prophet said: "Serve the Lord with fear, and rejoice with trembling before Him." (Ps. 2:11) And he speaks of the throne that burn seven lamps of fire, which are the seven spirits of God; indeed, the seven are the seven archangels among the angels. Clement states in the sixth Stromata, perhaps guided from this source to say these things, that the seven spirits are like torches of fire. For it has been said somewhere about angels: "He makes his angels spirits, and his ministers a flame of fire." (Ps. 103:4; Heb. 1:7) This is an allegory drawn from the divine Scripture, concerning what this passage is now speaking about.”