When the voice of the trumpet sounded long, and waxed louder and louder. This is a somewhat free translation; but it gives well the real meaning of the Hebrew. We may conclude that the trumpet's blast was not continuous.
It sounded when the manifestation began (Exodus 19:16). It sounded again, much louder and with a much more prolonged note, to herald the actual descent of God upon the mount. This time the sound was so piercing, so terrible, so intolerable, that Moses could no longer endure to keep silence, but burst out in speech.
Were his words those recorded in Hebrews 12:21—"I exceedingly fear and quake"—words not found now in the Old Testament—or were they others which have been wholly lost to us? It is impossible to say. His speech, however, had the effect of bringing the awful preparations to a close—"Moses spake, and God.
answered him by a voice, and the Lord came down upon Mount Sinai."