Exodus 19:12-13

12You are to set boundaries for the people all around, saying, ‘Be very careful not to go up onto the mountain, or touch the border of it. Whoever touches the mountain will surely be put to death.

13Not a hand is to touch it, but he will surely be stoned or shot through. Whether it is an animal or a man, it will not live.’ When the shofar sounds, they may come up to the mountain.”