Exodus 19:15-17

King James Version

¹⁵ And he said unto the people, Be ready against the third day: come not at your wives.

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

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