Exodus 19
17 Ref And Moses brought forth the people out of the camp to meet God; and they stood at the nether part of the mount.
18 Ref And mount Sinai, the whole of it, smoked, because Jehovah descended upon it in fire; and the smoke thereof ascended as the smoke of a furnace, and the whole mount quaked greatly.
19 Ref And when the voice of the trumpet waxed louder and louder, Moses spake, and God answered him by a voice.