Exodus:19:18-19
kjv@Exodus:19:18 @ 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 the whole mount quaked greatly.
kjv@Exodus:19:19 @ And when the voice of the trumpet sounded long, and waxed louder and louder, Moses spake, and God answered him by a voice.