Exodus 20:21

25. But now of the clouds, and voices, and lightnings, and the trumpet, and the smoke on Mount Sinai, when it was said, “And Mount Sinai was altogether on a smoke, because the Lord descended upon it in fire, and the smoke thereof ascended as the smoke of a furnace; and all the people that was in the camp trembled; and when the voice of the trumpet sounded long and waxed louder and louder, Moses spake, and God answered him by a voice.” And a little after, when the Law had been given in the ten commandments, it follows in the text, “And all the people saw the thunderings, and the lightnings, and the noise of the trumpet, and the mountain smoking.” And a little after, “And [when the people saw it,] they removed and stood afar off, and Moses drew near unto the thick darkness where God was, and the Lord said unto Moses,” etc. …

For as, when He threatens, He shows a dark cloud; as on Mount Sinai; for “Moses,” it is said, “entered into the cloud, and into the thick darkness; and as a vapor, so went up the smoke;”and the prophet said, when speaking of His threatening, “Dark water in clouds of the air;”, so here, because it was His desire not to alarm, but to teach, it is a bright cloud.

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. (But things that come hereafter are not such. For what is Sina to Heaven? And what the “fire which might be touched” to God who cannot be touched? For “God is a consuming fire.”, c. v. 29 .) 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.” ( Ex. xx. 19 .) What wonder as respects the people? He himself who entered into “the darkness where God was,” saith, “I exceedingly fear and quake.” ( Ex. xx. 21 .)

III. And great multitudes followed Him, and He healed them there, where the multitude was greater. If He had abode upon His own eminence, if He had not condescended to infirmity, if He had remained what He was, keeping Himself unapproachable and incomprehensible, a few perhaps would have followed Him, perhaps not even a few, possibly only Moses, and He only so far as to see with difficulty the Back Parts of God. For He penetrated the cloud, either being placed outside the weight of the body or being withdrawn from his senses; for how could he have gazed upon the subtlety, or the incorporeity, or I know not how one should call it, of God, being incorporate and using material eyes? But inasmuch as He strips Himself for us, inasmuch as He comes down (and speak of an exinanition, as it were, a laying aside and a diminution of His glory), He becomes by this comprehensible.