Ps 103:6

“Now, according to a Hebrew figure of speech, it is said of God in the eighteenth psalm that "he made darkness his secret place," to signify that those notions that should be worthily entertained of God are invisible and unknowable, because God conceals himself in darkness, as it were, from those who cannot endure the splendors of his knowledge or are incapable of looking at them, partly owing to the pollution of their understanding, which is clothed with the body of mortal lowliness, and partly owing to its feebler power of comprehending God. And in order that it may appear that the knowledge of God has rarely been vouchsafed to people and has been found in very few individuals, Moses is related to have entered into the darkness where God was. And again, with regard to Moses it is said, "Moses alone shall come near the Lord, but the rest shall not come near." And again, that the prophet may show the depth of the doctrines that relate to God and that are unattainable by those who do not possess the "Spirit that searches all things, even the deep things of God," he added, "The abyss like a garment is his covering." No, our Lord and Savior, the Logos of God, manifesting that the greatness of the knowledge of the Father, is appropriately comprehended and known preeminently by him alone, and in the second place by those whose minds are enlightened by the Logos and God, declares, "No one knows the Son but the Father; neither does any one know the Father but the Son, and he to whoever the Son will reveal him." For no one can worthily know the "uncreated" and firstborn of all created nature like the Father who begat him, nor any one the Father like the living Logos, and his Wisdom and Truth. By sharing in him who takes away from the Father what is called "darkness," which he "made his secret place," and "the abyss," which is called his "covering," and by unveiling the Father in this way, every one knows the Father who is capable of knowing him.”

“"The deep, like a garment, is its clothing." Whose? Is it perchance God's? But he had already said of His clothing, "Clothed with light as with a garment." I hear of God clothed in light, and that light, if we will, are we. What is, if we will? if we are no longer darkness. Therefore if God is clothed with light, whose clothing, again, is the deep? For an immense mass of waters is called the deep. All water, all the moist nature, and the substance everywhere shed abroad through the seas, and rivers, and hidden caves, is all together called by one name, the Deep. Therefore we understand the earth, of which he said, "He hath founded the earth." Of it I believe he said, "The deep, like a garment is its clothing." For the water is as it were the clothing of the earth, surrounding it and covering it. ...”

“You covered the deep as [with] a garment This is similar to what is said elsewhere (Job 38: 9): “When I made the cloud its raiment, etc.” the deep That is the sea. the waters stand on the mountains The waters of the ocean are higher than the whole world. They stand on the mountains, and so Scripture states (Amos 5:8, 9:6): “He who calls the water of the sea and pours it upon the face of the earth.” Pouring denotes only [pouring] from above downward.”