Exodus 19:9-16

9And Jehovah said to Moses, Lo, I will come to thee in the cloud's thick darkness, that the people may hear when I speak with thee, and believe thee also for ever. And Moses told the words of the people to Jehovah.

10And Jehovah said to Moses, Go to the people, and hallow them to-day and to-morrow, and let them wash their clothes;

11and let them be ready for the third day; for on the third day Jehovah will come down before the eyes of all the people on mount Sinai.

12And set bounds round about the people, saying, Take heed to yourselves, [not] to go up unto the mountain nor touch the border of it: whatever toucheth the mountain shall certainly be put to death:

13not a hand shall touch it, but it shall certainly be stoned, or shot through; whether it be a beast or a man, it shall not live. When the long drawn note of the trumpet soundeth, they shall come up to the mountain.

14And Moses came down from the mountain to the people, and hallowed 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.

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.