That the Heaven of Heavens Was an Intellectual Creature, But that the Earth Was Invisible and Formless Before the Days that It Was Made
9 And therefore the Spirit, the Teacher of Your servant when He relates that Thou did in the Beginning create heaven and earth, is silent as to times, silent as to days. For, doubtless, that heaven of heavens, which Thou in the Beginning created, is some intellectual creature, which, although in no wise co-eternal unto You, the Trinity, is yet a partaker of Your eternity, and by reason of the sweetness of that most happy contemplation of Yourself, does greatly restrain its own mutability, and without any failure, from the time in which it was created, in clinging unto You, surpasses all the rolling change of times. But this shapelessness— this earth invisible and without form— has not itself been numbered among the days. For where there is no shape nor order, nothing either comes or goes; and where this is not, there certainly are no days, nor any vicissitude of spaces of times.
Source: Confessions (New Advent)