Hebrews 12:18

While he brought out the fearsome things, he did not reveal the fruit springing from them. He did not say he "appeared," because what they saw was not the God of all in person but some impression of the divine coming.

There is fire, for this reason, that God may appear more fearsome to those who were delivering the law. "And to darkness and gloom." Darkness and gloom signify the shadow of the Old Testament. For if those were figures, it is evident that until the truth came, the figures were obscure, while it was not known what they signified. Moreover, darkness also signifies the invisibility of God. "and to darkness," he says, "under his feet." (Ps. 17:10) "and a storm." By the word, storm, he excites them when they were sluggish. Indeed, the storm is a twisting of the wind.

Wonderful indeed were the things in the Temple, the Holy of Holies; and again awful were those things also that were done at Mount Sinai, "the fire, the darkness, the blackness, the tempest." For, it says, "God appeared in Sinai," and long ago were these things celebrated. The New Covenant, however, was not given with any of these things, but has been given in simple discourse by God. See then how he makes the comparison in these points also. And with good reason has he put them afterwards. For when he had persuaded them by innumerable arguments, when he had also shown the difference between each covenant, then afterwards, the one having been already condemned, he easily enters on these points also. These things, he means, are terrible; and so terrible that they could not even bear to hear them, that not even "a beast" dared to go up. For it is said, "Let not God speak, but let Moses speak unto us. And so fearful was that which was commanded, Though even a beast touch the mountain, it shall be stoned; Moses said, I exceedingly fear and quake." What wonder as respects the people? He himself who entered into "the darkness where God was," saith, "I exceedingly fear and quake." Fearful were those things, but these are far more admirable and glorious. For here there is not "darkness," nor "blackness," nor "tempest." It seems to me that by these words he hints at the obscurity of the Old Testament, and the overshadowed and veiled character of the Law. And besides the Giver of the Law appears in fire terrible, and apt to punish those who transgress. But what are "the sounds of the trumpet"? Probably it is as though some King were coming. This at all events will also be at the second coming. "At the last trump" all must be raised. But it is the trumpet of His voice which effects this. At that time then all things were objects of sense, and sights, and sounds; now all are objects of understanding, and invisible. And, it says, "there was much smoke." For since God is said to be fire, and appeared thus in the bush, He indicates the fire even by the smoke. And what is "the blackness and the darkness"? He again expresses its fearfulness. Thus Isaiah also says; "And the house was filled with smoke." And what is the object of "the tempest"? The human race was careless. It was therefore needful that they should be aroused by these things. For no one was so dull as not to…