Exodus 19:16

And it came to pass on the third day in the morning, that there were thunders and lightnings, and a thick cloud upon the mount, and the voice of the trumpet exceeding loud; so that all the people that was in the camp trembled.

On the third day ... The descent of God was signalized by every object imagination can conceive connected with the ideas of grandeur and of awe. Although the Divine Being was animated with feelings of the tenderest consideration for His people, and this new dispensation was itself an eminent display of kindness and love, yet 'the law being added because of transgressions,' its inauguration was all in keeping with the economy about to be introduced. Since the mountain burned with fire, God was exhibited as a consuming fire to the transgressors of His law. The thunder and lightning, more awful amid the deep stillness of the region, and reverberating with terrific peals among the mountains, would rouse the universal attention: a thick cloud was an apt emblem of the dark and shadowy dispensation, (cf. Matthew 17:5; Judges 5:4; Psalms 68:7, where the sacred bards, alluding to the solemn and impressive scene on Sinai, mention, among the other phenomena, torrents of rain).

If it be asked, Why was the proclamation of the law accompanied by thunders and lightnings? the answer is, The law of Moses, which was a law of ordinances, and intended to impress a people accustomed to, and bent upon, idolatry, with the fear of God and a sense of His power, was delivered in such an imposing manner in order that the appalling phenomena on the mount might impress them with the indispensable need of a mediator. When the expected Mediator, therefore, appeared, according to God's promise, He would certainly not come in a way to frighten or to appall (cf. 1 Kings 19:11; Isaiah 42:3).

A cloud was the symbol of the divine presence. In the Scriptural accounts of the Deity's descent He is commonly said to come in the clouds; and there are passages in which it may be questioned whether this costume, designed to convey an impression of His regal majesty, is to be only figuratively understood (Psalms 18:9; Isaiah 6:4). But in the Theophany at Sinai there was no doubt a visible exhibition of these objects, which was perceived by the natural eyes of the Israelites (cf. Exodus 34:5).

The voice of the trumpet. The awfully impressive and solemnizing effects of the thunder-peals in such an amphitheater of gigantic mountains can be very inadequately conceived by us. Dr. Stewart ('Tent and Khan,' pp. 139, 140) enjoyed the rare opportunity of witnessing a thunder-storm in the Sinaitic region, which he describes as follows: 'Every bolt, as it burst with the roar of a cannon, seemed to awaken a series of distinct echoes on every side. They swept like a whirlwind among the higher mountains, becoming faint as some mighty peak intervened, and bursting with undiminished volume through some yawning cleft, until the very ground trembled with the concussion. It seemed as if the mountains of the whole peninsula were answering one another in a chorus of the deepest bass. Ever and anon a flash of lightning dispelled the pitchy darkness and lit up the mount as if it had been day; then, after the interval of a few seconds, came the peal of thunder, bursting like a shell, to scatter its echoes to the four quarters of the heavens, and overpowering for a moment the loud howlings of the wind.'

The reverberation of the thunder-peals among the mountains and wadys of Sinai was as Mr. Drew ('Scripture Lands,' p. 124) remarks, from having witnessed a thunder-storm in the Sinaitic region, exactly like the sound of a trumpet; and this is the way-a most natural and obvious way-of explaining the clause with reference to "the voice of the trumpet exceeding loud." Some ascribe it to angels (cf. 1 Corinthians 15:52; 1 Thessalonians 4:16). This gave the scene the character of a miraculous transaction, in which other elements than those of nature were at work, and some other than material trumpet was blown by other means than human breath.