Clement of Alexandria, on Rev 6:9

“And when he had opened the fifth seal, I saw under the altar the souls of them that were slain for the word of God, and for the testimony which they held.”

“But for those who are white and unstained within, it is most suitable to use white and simple garments. Clearly and plainly, therefore, Daniel the prophet says, "Thrones were set, and upon them sat one like the Ancient of days, and His vesture was white as snow." The Apocalypse says also that the Lord Himself appeared wearing such a robe. It says also, "I saw the souls of those that had witnessed, beneath the altar, and there was given to each a white robe." And if it were necessary to seek for any other colour, the natural colour of truth should suffice.”

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