Ezekiel 1:13,14

As for the likeness of the living creatures Their colour, or aspect; their appearance was like burning coals They were inflamed by the Spirit of God with a holy zeal for his glory, and with indignation against impenitent sinners. This might also be intended as a symbolical declaration, that after the long patience of God, all things now tended to vengeance, and the executing of his judgments upon the Jews; for executing which he would use these angels as ministers. And like the appearance of lamps This probably signified, that the uprightness of the divine justice should shine forth, or be made manifest in these judgments. It went up and down among the living creatures That is, the fire moved itself up and down. Milton's expression, (Paradise Lost, 6:756,) is, “And careening fires between.” That is, fires which ran swiftly, and, as it were, tilted at each other: emblematical of the terrible effects of the ministry of these living creatures on the objects of divine vengeance. Out of the fire went forth lightning Significative of the irresistible force of the divine judgments, and the terrible and sudden destruction to be produced by them. And the living creatures ran and returned as a flash of lightning With inexpressible velocity: the swiftness of their motions every way resembled flashes of lightning. “They ran to do their work, and execute their orders,” says Henry, “and then returned to give an account of what they had done, and receive new instructions. They ran into the lower world, to do what was to be done there: and when they had done, returned as a flash of lightning, to the upper world, to the vision of God. Thus we should be in the affairs of this world: though we run into them, we must not repose in them, but our souls must presently return like lightning to God, their rest and centre.”