Concerning the Ten Commandments, which are the Heads of the Law (44)

And, moreover, as was natural, he filled the whole place with miraculous signs and works, with noises of thunder too great for the hearing to support, and with the most radiant brilliancy of flashes of lightning, and with the sound of an invisible trumpet extending to a great distance, and with the march of a cloud, which, like a pillar, had its foundation fixed firmly on the earth, but raised the rest of its body even to the height of heaven; and, last of all, by the impetuosity of a heavenly fire, which overshadowed everything around with a dense smoke. For it was fitting that, when the power of God came among them, none of the parts of the world should be quiet, but that everything should be put in motion to minister to his service.