In this verse also the Prophet confirms the vision, because God always gave signs of his presence. But it seems also to have another object, since the cherubim by the sound of their wings point out a remarkable change, both unusual and incomprehensible. For he says, there was a noise which shook the place, just as if God was speaking. When therefore we hear God's voice, the Prophet means to say, it is just as if God thundered from heaven and made the whole world tremble; for no concussion can be more severe than that sound of the cherubims' wings. From this a certain wonderful change must be perceptible, since God so filled his Prophet with terror, that he should be a messenger and witness of it to all others.