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. There were all the signs of an unusual, supernatural thunder-shower. The darkness indicated that the holy God is unapproachable, yeiling Himself from mortals even when He discloses Himself, for it is impossible for sinners to look upon His open glory. And the voice of the trumpet (was) exceeding loud, so that all the people that was in the camp trembled. The blasts of the horn, terrifying in themselves, became doubly so since their source was the divine presence on the mountain, where the Lord had now come down with His holy angels to make known His holy will, Deuteronomy 33:2; Acts 7:53; Galatians 3:19. No wonder the people heard the sound only with great fear and trembling.
Related Commentaries of Exodus 19:16
Exodus 19:16
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.