Exodus 19:16-18

16On the morning of the third day, there was thunder and lightning. A thick cloud was there over the mountain. The people heard the noise of a loud trumpet. They were so afraid that their bodies were shaking.

17Then Moses led the people away from their tents to meet with God. They went and they stood at the edge of the mountain.

18Smoke covered Sinai mountain because the Lord had come down on the mountain, like a fire. The smoke rose up from the mountain, like smoke from a great fire. The whole mountain shook very much.