Heaven and Earth Were Made In the Beginning; Afterwards the World, During Six Days, from Shapeless Matter
8 But that heaven of heavens was for You, O Lord; but the earth, which You have given to the sons of men, to be seen and touched, was not such as now we see and touch. For it was invisible and “without form,” and there was a deep over which there was not light; or, darkness was over the deep, that is, more than in the deep. For this deep of waters, now visible, has, even in its depths, a light suitable to its nature, perceptible in some manner unto fishes and creeping things in the bottom of it.
But the entire deep was almost nothing, since hitherto it was altogether formless; yet there was then that which could be formed. For Thou, O Lord, hast made the world of a formless matter, which matter, out of nothing, You have made almost nothing, out of which to make those great things which we, sons of men, wonder at. For very wonderful is this corporeal heaven, of which firmament, between water and water, the second day after the creation of light, Thou said, Let it be made, and it was made. Which firmament You called heaven, that is, the heaven of this earth and sea, which You made on the third day, by giving a visible shape to the formless matter which You made before all days.
For even already had Thou made a heaven before all days, but that was the heaven of this heaven; because in the beginning You had made heaven and earth. But the earth itself which You had made was formless matter, because it was invisible and without form, and darkness was upon the deep. Of which invisible and formless earth, of which formlessness, of which almost nothing, You might make all these things of which this changeable world consists, and yet consists not; whose very changeableness appears in this, that times can be observed and numbered in it. Because times are made by the changes of things, while the shapes, whose matter is the invisible earth aforesaid, are varied and turned.
Source: Confessions (New Advent)