Exodus 19:9-20

9And the Lord said to Moses, “Behold, I come to you in the thick cloud, that the people may hear when I speak with you, and believe you forever.” So Moses told the words of the people to the Lord.

10Then the Lord said to Moses, “Go to the people and consecrate them today and tomorrow, and let them wash their clothes.

11And let them be ready for the third day. For on the third day the Lord will come down upon Mount Sinai in the sight of all the people.

12You shall set bounds for the people all around, saying, ‘Take heed to yourselves that you do not go up to the mountain or touch its base. Whoever touches the mountain shall surely be put to death.

13Not a hand shall touch him, but he shall surely be stoned or shot with an arrow; whether man or beast, he shall not live.’ When the trumpet sounds long, they shall come near the mountain.”

14So Moses went down from the mountain to the people and sanctified the people, and they washed their clothes.

15And he said to the people, “Be ready for the third day; do not come near your wives.”

16Then it came to pass on the third day, in the morning, that there were thunderings and lightnings, and a thick cloud on the mountain; and the sound of the trumpet was very loud, so that all the people who were in the camp trembled.

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

18Now Mount Sinai was completely in smoke, because the Lord descended upon it in fire. Its smoke ascended like the smoke of a furnace, and the whole mountain quaked greatly.

19And when the blast of the trumpet sounded long and became louder and louder, Moses spoke, and God answered him by voice.

20Then the Lord came down upon Mount Sinai, on the top of the mountain. And the Lord called Moses to the top of the mountain, and Moses went up.