Exodus 19:21-25

The LORD said to Moses, “Go down and warn the people that they must not force their way through to see me. If they do, many of them will die. Even the priests, who may come near me, must first prepare themselves. If they don’t, I, the LORD, will punish them.” Moses told the LORD, “The people cannot come up on Mount Sinai, because you yourself told us, ‘Set a limit around the mountain, and set it apart as holy.’ ” The LORD said to him, “Go down and bring Aaron up with you, but don’t allow the priests or the people to force their way through. They must not come up to the LORD, or I will punish them.” So Moses went down to the people and told them these things.