That Creatures are Mutable and God Alone Immutable. · NPNF1-01. The Confessions and Letters of St. Augustine, with a Sketch of his Life and Work

And I viewed the other things below Thee, and perceived that they neither altogether are, nor altogether are not. They are, indeed, because they are from Thee; but are not, because they are not what Thou art. For that truly is which remains immutably. It is good, then, for me to cleave unto God, for if I remain not in Him, neither shall I in myself; but He, remaining in Himself, reneweth all things. And Thou art the Lord my God, since Thou standest not in need of my goodness.