You have seen what I did to the Egyptians, and how I bore you on eagles' wings and brought you to myself.
Now therefore, if you obey my voice and keep my covenant, you shall be my treasured possession out of all the peoples. Indeed, the whole earth is mine,
but you shall be for me a priestly kingdom and a holy nation. These are the words that you shall speak to the Israelites."
So Moses came, summoned the elders of the people, and set before them all these words that the Lord had commanded him.
The people all answered as one: "Everything that the Lord has spoken we will do." Moses reported the words of the people to the Lord.
Then the Lord said to Moses, "I am going to come to you in a dense cloud, in order that the people may hear when I speak with you and so trust you ever after." When Moses had told the words of the people to the Lord,
the Lord said to Moses: "Go to the people and consecrate them today and tomorrow. Have them wash their clothes
and prepare for the third day, because on the third day the Lord will come down upon Mount Sinai in the sight of all the people.
You shall set limits for the people all around, saying, "Be careful not to go up the mountain or to touch the edge of it. Any who touch the mountain shall be put to death.
No hand shall touch them, but they shall be stoned or shot with arrows; whether animal or human being, they shall not live.' When the trumpet sounds a long blast, they may go up on the mountain."
References for Exodus 19:13
So Moses went down from the mountain to the people. He consecrated the people, and they washed their clothes.