As the appearance of the bow that is in the cloud in the day of rain, so was the appearance of the brightness round about. This was the appearance of the likeness of the glory of the LORD. And when I saw it, I fell upon my face, and I heard a voice of one that spake. As the appearance of the bow - Over the canopy on which this glorious personage sat there was a fine rainbow, which, from the description here, had all its colors vivid, distinct, and in perfection - red, orange, yellow, green, blue, indigo, and violet. In all this description we must understand every metal, every color, and every natural appearance, to be in their utmost perfection of shape, color, and splendor. "And this," as above described, "was the appearance of the likeness of the glory of the Lord." Splendid and glorious as it was, it was only the "appearance of the likeness," a faint representation of the real thing.
I have endeavored to explain these appearances as correctly as possible; to show their forms, positions, colors, etc. But who can explain their meaning? We have conjectures in abundance; and can it be of any use to mankind to increase the number of those conjectures? I think not. I doubt whether the whole does not point out the state of the Jews, who were about to be subdued by Nebuchadnezzar, and carried into captivity. And I am inclined to think that the "living creatures, wheels, fires, whirlwinds," etc., which are introduced here, point out, emblematically, the various means, sword, fire, pestilence, famine, etc., which were employed in their destruction; and that God appears in all this to show that Nebuchadnezzar is only his instrument to inflict all these calamities. What is in the following chapter appears to me to confirm this supposition. But we have the rainbow, the token of God's covenant, to show that though there should be a destruction of the city, temple, etc., and sore tribulation among the people, yet there should not be a total ruin; after a long captivity they should be restored. The rainbow is an illustrious token of mercy and love.
Commentary on the Bible, by Adam Clarke [1831].