Exodus 19:9-11

21st Century King James Version

⁹ And the Lord said unto Moses, “Lo, I come unto thee in a thick cloud, that the people may hear when I speak with thee, and believe thee for ever.” And Moses told the words of the people unto the Lord.

¹⁰ And the Lord said unto Moses, “Go unto the people and sanctify them today and tomorrow, and let them wash their clothes

¹¹ and be ready against the third day; for the third day the Lord will come down in the sight of all the people upon Mount Sinai.