Exodus 19:16-25 New American Bible (Revised Edition) (NABRE)
The Great Theophany. 16 On the morning of the third day there were peals of thunder and lightning, and a heavy cloud over the mountain, and a very loud blast of the shofar,[a] so that all the people in the camp trembled. 17 But Moses led the people out of the camp to meet God, and they stationed themselves at the foot of the mountain. 18 Now Mount Sinai was completely enveloped in smoke, because the Lord had come down upon it in fire. The smoke rose from it as though from a kiln, and the whole mountain trembled violently. 19 The blast of the shofar grew louder and louder, while Moses was speaking and God was answering him with thunder.
20 [b]When the Lord came down upon Mount Sinai, to the top of the mountain, the Lord summoned Moses to the top of the mountain, and Moses went up. 21 Then the Lord told Moses: Go down and warn the people not to break through to the Lord in order to see him; otherwise many of them will be struck down. 22 For their part, the priests, who approach the Lord must sanctify themselves; else the Lord will break out in anger against them. 23 But Moses said to the Lord, “The people cannot go up to Mount Sinai, for you yourself warned us, saying: Set limits around the mountain to make it sacred.” 24 So the Lord said to him: Go down and come up along with Aaron. But do not let the priests and the people break through to come up to the Lord; else he will break out against them.” 25 So Moses went down to the people and spoke to them.