Exodus 19:8-10

Amplified Bible

⁸ All the people answered together and said, “We will do everything that the Lord has spoken.” And Moses reported the words of the people to the Lord. ⁹ The Lord said to Moses, “Behold, I will come to you in a thick cloud, so that the people may hear when I speak with you and may believe and trust in you forever.” Then Moses repeated the words of the people to the Lord.

¹⁰ The Lord also said to Moses, “Go to the people and consecrate them today and tomorrow [that is, prepare them for My sacred purpose], and have them wash their clothes