Exodus 19:7-11

So Moses came and called the elders of the people and set before them all these words that the LORD had commanded him. All the people answered together and said, “All that the LORD has spoken we will do.” And Moses reported the words of the people to the LORD. And the LORD said to Moses, “Behold, I am coming to you in a thick cloud, that the people may hear when I speak with you, and may also believe you forever.” When Moses told the words of the people to the LORD, the LORD said to Moses, “Go to the people and consecrate them today and tomorrow, and let them wash their garments and be ready for the third day. For on the third day the LORD will come down on Mount Sinai in the sight of all the people.