Contra Faustum Manichaeum, XXVI, Chap. iii. St Augustine goes on to explain himself in apt accordance with text and notes preceding: "We call 'nature' the course of nature, that we know and are accustomed to. When God does anything contrary to this course, such doings are called extraordinary, or marvellous. But against that supreme law of nature, which is hidden from the knowledge as well of the wicked as of others who are still weak, God is as far removed from ever doing anything as He is removed from doing anything against Himself."
Of God and His Creatures: 3.100