John Chrysostom : "And when forty years were expired, there appeared to him in the wilderness of mount Sinai an angel of the Lord in a flame of fire in a bush." Do you mark that it is not hindered by lapse of time? For when he was an exile, when a stranger, when he had now passed much time in a foreign land, so as to have two sons, when he no longer expected to return, then does the Angel appear to him. The Son of God he calls an Angel, as also he calls Him man. Appears in the desert, not in a temple. See how many miracles are taking place, and no word of Temple, no word of Sacrifice. And here also not simply in the desert, but in the bush. "When Moses saw it, he wondered at the sight: and as he drew near to behold it, the voice of the Lord came unto him." Lo! he was deemed worthy of the Voice also. — Homily on Acts 16 Oecumenius : Now he calls the Son of God an angel, just as elsewhere he calls him a man. For he is the angel of great counsel. (Isa. 9:6 LXX) Therefore shortly afterwards he shows him speaking to the blessed Moses: "I am the God of your fathers, the God of Abraham, and of Isaac, and of Jacob." He is revealed in a flame of fire in a bush. For in the form of fire and on Mount Sinai God appears while giving the law. What then does the passage mean? The sacred text likens the divine nature to fire because it overpowers wood and grass, that is, man. For it says somewhere: "God is a consuming fire." (Deut. 4:24; Heb. 12:29) And again, "Man, his days are as grass." (Ps. 103:15) But just as fire is not carried off by thorns, so deity is not borne away by humanity. Yet in Christ it happened and became as if subdued, a kind of surrounding of the unmingled assault of the fire of his own nature, so that it might be able to be held, just as fire is by thorns. That the fire upon the bush, having kept the wood entirely unconsumed, might mysteriously indicate that he made his own flesh stronger than corruption, for the deity had taken up residence in humanity. And this mystery occurred in Christ. — Commentary on Acts