Exodus 19:8-10

King James Version

⁸ And all the people answered together, and said, All that the Lord hath spoken we will do. And Moses returned the words of the people unto the Lord.

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 to day and to morrow, and let them wash their clothes,