Exodus 19:22-25

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.” 19:25 So Moses went down to the people and spoke to them.