The discourse which we utter, which we use in conversation with each other, is incorporeal, imperceptible, impalpable; but clothed in letters and characters, it becomes material, perceptible, tangible. So too the Word of God, which was naturally invisible, becomes visible, and that comes before us in tangible form, which was by nature incorporeal.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: P. iii. Hom. Theod. Ancyr. de Nat. Dom.