Exodus 19:9-10 NKJV
And the LORD said to Moses, “Behold, I come to you in the thick cloud, that the people may hear when I speak with you, and believe you forever.”
So Moses told the words of the people to the LORD.
Then the LORD said to Moses, “Go to the people and consecrate them today and tomorrow, and let them wash their clothes.
NKJV: New King James Version