Exodus 33:18

“Be not elated on account of thy wisdom,” say the Proverbs. “In all thy ways acknowledge her, that she may direct thy ways, and that thy foot may not stumble.” By these remarks he means to show that our deeds ought to be conformable to reason, and to manifest further that we ought to select and possess what is useful out of all culture. Now the ways of wisdom are various that lead right to the way of truth. Faith is the way. “Thy foot shall not stumble” is said with reference to some who seem to oppose the one divine administration of Providence. Whence it is added, “Be not wise in thine own eyes,” according to the impious ideas which revolt against the administration of God. “But fear God,” who alone is powerful. Whence it follows as a consequence that we are not to oppose God. …

Wherefore also Moses says, “Show Thyself to me,”, intimating most clearly that God is not capable of being taught by man, or expressed in speech, but to be known only by His own power. For inquiry was obscure and dim; but the grace of knowledge is from Him by the Son. Most clearly Solomon shall testify to us, speaking thus: “The prudence of man is not in me: but God giveth me wisdom, and I know holy things.” Now Moses, describing allegorically the divine prudence, called it the tree of life planted in Paradise; which Paradise may be the world in which all things proceeding from creation grow. In it also the Word blossomed and bore fruit, being “made flesh,” and gave life to those “who had tasted of His graciousness;” since it was not without the wood of the tree that He came to our knowledge. For our life was hung on it, in order that we might believe. …

You ought to be very much ashamed of yourself on this account too, for permitting him to appear on the retired mountain in the company of Moses and Elias, whom he had come to destroy. This, to be sure, was what he wished to be understood as the meaning of that voice from heaven: “This is my beloved Son, hear Him”, Him , that is, not Moses or Elias any longer. The voice alone, therefore, was enough, without the display of Moses and Elias; for, by expressly mentioning whom they were to hear, he must have forbidden all others from being heard. …

On the other hand, he whose “heart” was habitually found “lifted up” rather than fattened up, who in forty days and as many nights maintained a fast above the power of human nature, while spiritual faith subministered strength (to his body), both saw with his eyes God’s glory, and heard with his ears God’s voice, and understood with his heart God’s law: while He taught him even then (by experience) that man liveth not upon bread alone, but upon every word of God; in that the People, though fatter than he, could not constantly contemplate even Moses himself, fed as he had been upon God, nor his leanness, sated as it had been with His glory! Deservedly, therefore, even while in the flesh, did the Lord show Himself to him, the colleague of His own fasts, no less than to Elijah. …

28. Add, too, that which the Lord afterward said to Moses, “Thou canst not see my face: for there shall no man see my face, and live. And the Lord said, Behold, there is a place by me, and thou shall stand upon a rock: and it shall come to pass, while my glory passeth by, that I will put thee into a watch-tower of the rock, and will cover thee with my hand while I pass by: and I will take away my hand, and thou shalt see my back parts; but my face shall not be seen.”