Having said that we are made the sons of God, and in no other way than because the Word was made flesh; he mentions another gift, And we saw His glory. Which glory we should not have seen, had He not, by His alliance with humanity, become visible to us. For if they could not endure to look on the glorified face of Moses, but there was need of a veil, how could soiled and earthly creatures, like ourselves, have borne the sight of undisguised Divinity, which is not vouchsafed even to the higher powers themselves.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: Hom. xii. [xi.] 1.