Exodus 19:18-20 Holman Christian Standard Bible (HCSB)
18 Mount Sinai was completely enveloped in smoke because the Lord came down on it in fire. Its smoke went up like the smoke of a furnace, and the whole mountain shook violently. 19 As the sound of the trumpet grew louder and louder, Moses spoke and God answered him in the thunder.
20 The Lord came down on Mount Sinai at the top of the mountain. Then the Lord summoned Moses to the top of the mountain, and he went up.