Exodus 19:10-13

The LORD said to Moses, “Go to the people and have them spend today and tomorrow preparing themselves. They must wash their clothes and be ready by the day after tomorrow. On that day I, the LORD, will come down on Mount Sinai, and all the people will see me. But you must set a limit around the mountain that the people are not to cross. Tell them not to go up on the mountain and not to touch the foot of it. Anyone who touches the mountain must be put to death with stones or shot with arrows. No one is allowed to touch him. Whether it is a person or an animal, he will not live. But the trumpet will make a long blast, and only then may the people go up on the mountain.”