Cyril of Jerusalem

Moses says to him, "Show me yourself." You see that then also the prophets saw Christ, that is, in the measure each was able. "Show me yourself, that I may see you clearly." But he said, "No one sees me and still lives." Therefore, because no one could see the face of the Godhead and live, he assumed the face of human nature, that seeing this we might live. Yet when he wished to show even this with a little majesty, at the time when "his face shone as the sun," the disciples fell to the earth terrified. …

Catechetical Lecture 10.7 ↗

Clement of Alexandria

As a result Moses, convinced that God will never be known to human wisdom, says, "Reveal yourself to me," and finds himself forced to enter "into the darkness" where the voice of God was present; in other words, into the unapproachable, imageless, intellectual concepts relating to ultimate reality. For God does not exist in darkness. He is not in space at all. He is beyond space and time and anything belonging to created beings. Similarly he is not found in any section. He contains nothing. He is contained by nothing. …

The Stromata Book 2 ↗

Augustine of Hippo

Again, in ancient times, in the case of the faithful servant of God, Moses, who was destined to labor on this earth and to rule the chosen people, it would not be surprising that what he asked was granted: that he might see the glory of the Lord, to whom he said, "If I have found favor before you, show me yourself openly." He received an answer adapted to present conditions: that he could not see the face of God, because no man could see him and live. Thus God made clear that the vision belongs to another and better life. …

Letter 147.32 ↗