Exodus 19:12-13

12Mark off a boundary all around the mountain. Warn the people, ‘Be careful! Do not go up on the mountain or even touch its boundaries. Anyone who touches the mountain will certainly be put to death.

13No hand may touch the person or animal that crosses the boundary; instead, stone them or shoot them with arrows. They must be put to death.’ However, when the ram’s horn sounds a long blast, then the people may go up on the mountain.”