Augustine of Hippo : Who can doubt that here too God appeared to the eyes of mortal men by a corporeal creature made subject to him and not by his own substance? But it is also not apparent whether it was the Father, or the Son, or the Holy Spirit, or the Trinity itself, the one God. Nor, as far as I can judge, has this distinction been made in that place where it is written: "And the glory of the Lord appeared in the cloud, and the Lord spoke to Moses saying, 'I have heard the grumbling of the children of Israel.' " — THE TRINITY 2.14.24 Bede : The freeing of the children of Israel and their being brought out into the fatherland once promised them is also linked with the mystery of our redemption. By means of it we make our way to the light of the dwelling place on high with the grace of Christ lighting our way and guiding us. That cloud and column of fire that both protected them throughout the whole of their journey from the darkness of the nights and led them by a sure path to the promised homes of the fatherland also prefigured the light of this grace. — Commentary on the Catholic Epistles, 1 Peter 2:9 Gregory the Dialogist : It was also fitting that a pillar of fire preceded the Israelites as they progressed through the desert during the night and a pillar of a cloud during the day. There is dread in fire but a gentle soothing quality in the sight of a cloud. "Day" is understood to point toward the life of the righteous and "night" that of the sinner. Hence Paul said to sinners who had been converted, "You were once darkness but are now light in the Lord." The pillar was revealed as a cloud during the day and as a fire during the night since almighty God will appear soothing to the righteous and dreadful to the unrighteous. When he comes at the judgment, he will reassure the former by his gentleness and mildness and cause dread in the latter by the strictness of his justice. — Forty Gospel Homilies, Homily 21 Peter Chrysologus : At one time he appears all aglow in a bush. For you are cold with the perfidy of infidelity, and he wants to enkindle you with the heat of faith. At another time he glows like fire in a pillar extending toward heaven, that the darkness of your ignorance may be removed and that you can follow the way of saving knowledge through the wilderness of this world. At yet another time he is changed for you into a pillar of cloud, in order to restrain the burning ebullience of your passions. — SERMON 170