Exodus 19:20-22

Living Bible

²⁰ So the Lord came down upon the top of Mount Sinai and called Moses up to the top of the mountain, and Moses ascended to God.

²¹ But the Lord told Moses, “Go back down and warn the people not to cross the boundaries. They must not come up here to try to see God, for if they do, many of them will die. ²² Even the priests on duty^[a] must sanctify themselves, or else I will destroy them.”