Exodus 19:16-18

MLV(i) 16 And it happened on the third day, when it was morning, that there were thunders and lightnings and a thick cloud upon the mountain and the voice of an exceedingly loud trumpet. And all the people who were in the camp trembled.
17 And Moses brought out the people out of the camp to meet God and they stood at the lower part of the mountain. 18 And Mount Sinai, the whole of it, smoked, because Jehovah descended upon it in fire and the smoke of it ascended as the smoke of a furnace. And the whole mountain quaked greatly.