Exodus 19:9

9 The LORD said to Moses, “I am going to come to you in a dense cloud, so that the people will hear me speaking with you and will always put their trust in you.” Then Moses told the LORD what the people had said.

Read Exodus 19:9 Using Other Translations

And the LORD said unto Moses, Lo, I come unto thee in a thick cloud, that the people may hear when I speak with thee, and believe thee for ever. And Moses told the words of the people unto 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,
Then the LORD said to Moses, “I will come to you in a thick cloud, Moses, so the people themselves can hear me when I speak with you. Then they will always trust you.” Moses told the LORD what the people had said.