When commenting on Rev 7:14:
And it says that they washed
their robes and made them white in the blood of the Lamb; indeed, it was
more fitting for the robes dyed in blood to become crimson rather than white.
How then have they become white? Because baptism, which is accomplished through
the death of the Lord, as it seems to the most wise Paul (Rom. 6:3), acts as a
cleanser of all impurity arising from sin, rendering those who are baptized in
it white and pure. (Commentary
on Revelation by Oecumenius [trans. John Litteral; 2026], 97)
