Exodus 19:16-24

19:16 On the third day in the morning there was thunder and lightning and a dense cloud on the mountain, and the sound of a very loud horn; all the people who were in the camp trembled. 19:17 Moses brought the people out of the camp to meet God, and they took their place at the foot of the mountain. 19:18 Now Mount Sinai was completely covered with smoke because the Lord had descended on it in fire, and its smoke went up like the smoke of a great furnace, and the whole mountain shook violently. 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. 19:22 Let the priests also, who approach the Lord, sanctify themselves, lest the Lord break through against them.”

19:23 Moses said to the Lord, “The people are not able to come up to Mount Sinai, because you solemnly warned us, ‘Set boundaries for the mountain and set it apart.’” 19:24 The Lord said to him, “Go, get down, and come up, and Aaron with you, but do not let the priests and the people force their way through to come up to the Lord, lest he break through against them.”