Exodus 19:18-19
Read this passage and open each verse for the full verse feed and commentary tools.
18And Mount Sinai was wrapped in smoke, because the LORD descended upon it in fire; and the smoke of it went up like the smoke of a kiln, and the whole mountain quaked greatly. 19And as the sound of the trumpet grew louder and louder, Moses spoke, and God answered him in thunder.
Exodus 19:18-19 (RSV)