Exodus 19:7

3 Then Moses went up to God, and the LORD called to him from the mountain, “This is what you are to tell the house of Jacob and explain to the sons of Israel:

4 ‘You have seen for yourselves what I did to Egypt, and how I carried you on eagles’ wings and brought you to Myself.

5 Now if you will indeed obey My voice and keep My covenant, you will be My treasured possession out of all the nations—for the whole earth is Mine.

6 And unto Me you shall be a kingdom of priests and a holy nation.’ These are the words that you are to speak to the Israelites.”

7 So Moses went back and summoned the elders of the people and set before them all these words that the LORD had commanded him.

8 And all the people answered together, “We will do everything that the LORD has spoken.” So Moses brought their words back to the LORD.

9 The LORD said to Moses, “Behold, I will come to you in a dense cloud, so that the people will hear when I speak with you, and they will always put their trust in you.” And Moses relayed to the LORD what the people had said.

10 Then the LORD said to Moses, “Go to the people and consecrate them today and tomorrow. They must wash their clothes

11 and be prepared by the third day, for on the third day the LORD will come down on Mount Sinai in the sight of all the people.

Read all of Exodus 19