Exodus 19:21-24

21Then the Lord spoke to Moses: “Go down, 1warn the people, so that 2they do not break through to the Lord to stare, and many of them 3perish.

22Also have the 4priests who approach the Lord consecrate themselves, or else the Lord will break out against them.”

23And Moses said to the Lord, “The people cannot come up to Mount Sinai, for You 5warned us, saying, ‘6Set boundaries around the mountain and consecrate it.’”

24Then the Lord said to him, “7Go down and come up again, 8you and Aaron with you; but do not let the 9priests and the people break through to come up to the Lord, or He will break out against them.”