You must not suppose, however, that He was in the world in the same sense in which the earth, cattle, men, are in the world; but in the sense in which an artificer controls his own work; whence the text, And the world was made by Him. Nor again did He make it after the manner of an artificer; for whereas an artificer is external to what he fabricates, God pervades the world, carrying on the work of creation in every part, and never absent from any part: by the presence of His Majesty He both makes and controls what is made. Thus He was in the world, as He by Whom the world was made.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: Tr. ii. c. 10