The Manichæans suppose the sun of the natural world to be our Lord Christ; but the Catholic Church reprobates such a notion; for our Lord Christ was not made the sun, but the sun was made by Him: inasmuch as all things were made by Him. (c. 1:3) And for our sake did He come to be under the sun, being the light which made the sun: He hid Himself under the cloud of the flesh, not to obscure, but to temper His light. Speaking then through the cloud of the flesh, the Light unfailing, the Light of wisdom says to men, I am the Light of the world.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: Tract. xxxiv. 2