Exodus 19:19-21

19:19 When the sound of the horn grew louder and louder, Moses was speaking and God was answering him with a voice.

19:20 The Lord came down on Mount Sinai, on the top of the mountain, and the Lord summoned Moses to the top of the mountain, and Moses went up. 19:21 The Lord said to Moses, “Go down and solemnly warn the people, lest they force their way through to the Lord to look, and many of them perish.