Ezekiel 1:21

And this whole vision is: a Spirit lifting up, and a great cloud, and four living creatures, and wheels following the same creatures, and the spirit, which deserve to be under the firmament of God. And after they were lifted up, and heard a voice like many waters, and like the sublime word of God, and the voice of camps and armies, they let down their wings, and showed astonishment in silence.

Concerning these wheels the same prophet repeats and adds: "When they went, they went, and when they stood, they stood; and when they were lifted up from the earth, the wheels were likewise lifted up following them, because the spirit of life was in the wheels." As you know, dearest brothers, these things have already been said for the most part, but they are narrated through repeated description. Therefore let it not weary us to repeat briefly in exposition what the Spirit deigned to narrate repeatedly through the prophet. For this alone is added as new in these words, namely what was said: "When they stood still, they stood still." Now there are certain people who advance to the point that they know how to dispense well the earthly goods they have received, who devote themselves to works of mercy, who come to the aid of the oppressed. These indeed go forward, in that they extend themselves for the benefit of their neighbor. With these, therefore, the wheels move, because the sacred words arrange the steps of their sayings in their journey. And there are others who are so strong in holding to the faith they have received that they are able to resist any adversities, and not only are they not in the least drawn toward the perversity of faithlessness, but they even fight against those who speak perversely and draw them back to rectitude. With these who stand still, the wheels also stand still, because the words of sacred Scripture confirm their rectitude, when they hear in them: "Stand firm and hold to the traditions you have learned." And again: "Your adversary the devil, like a roaring lion, goes about seeking whom he may devour; resist him, strong in faith." And there are others who despise all earthly things, who deign to possess nothing that passes away, and suspend themselves in the contemplation of God, as was said before. With these who are lifted up, therefore, the wheels are likewise raised, because to the extent that anyone has advanced to higher things, to that extent the sacred words speak to him of loftier matters. The living creatures go, therefore, for the benefit of their neighbor; they stand still for the guarding of themselves; they are lifted up for the contemplation of God. But the wheels likewise go, stand, and are lifted up, because sacred Scripture is found to be such as he himself becomes who seeks it. For you have advanced to the…