Exodus 19:12-19

12And thou shalt set bounds unto the people round about, saying, Take heed to yourselves, that ye go not up into the mount, or touch the border of it: whosoever toucheth the mount shall be surely put to death:

13no hand shall touch him, but he shall surely be stoned, or shot through; whether it be beast or man, it shall not live: when the trumpet soundeth long, they shall come up to the mount.

14And Moses went down from the mount unto the people, and sanctified the people; and they washed their garments.

15And he said unto the people, Be ready against the third day: come not near a woman.

16And it came to pass on the third day, when it was morning, that there were thunders and lightnings, and a thick cloud upon the mount, and the voice of a trumpet exceeding loud; and all the people that were in the camp trembled.

17And Moses brought forth the people out of the camp to meet God; and they stood at the nether part of the mount.

18And mount Sinai was altogether on smoke, because the LORD descended upon it in fire: and the smoke thereof ascended as the smoke of a furnace, and the whole mount quaked greatly.

19And when the voice of the trumpet waxed louder and louder, Moses spake, and God answered him by a voice.