Exodus 19:16-19

16And it came to pass on the third day, when it was morning, that there were thunders and lightnings and a heavy cloud on the mountain, and the sound of the trumpet exceeding loud; and the whole people that was in the camp trembled.

17And Moses brought the people out of the camp to meet with 1God; and they stood at the foot of the mountain.

18And the whole of mount Sinai smoked, because Jehovah descended on it in fire; and its smoke ascended as the smoke of a furnace; and the whole mountain shook greatly.

19And the sound of the trumpet increased and became exceeding loud; Moses spoke, and 2God answered him by a voice.