Exodus 19:16 ASV

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

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

¹⁶  And 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.

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

¹⁸  And mount Sinai, the whole of it, smoked, because Jehovah descended upon it in fire; and the smoke thereof ascended as the smoke of a furnace, and the whole mount quaked greatly.