Exodus 19:12; Exodus 19:13

12 "You shall set bounds for the people all around, saying, 'Beware that you do not go up on the mountain or touch the border of it; whoever touches the mountain shall surely be put to death.

13 'No hand shall touch him, but he shall surely be stoned or shot through; whether beast or man, he shall not live.' When the ram's horn sounds a long blast, they shall come up to the mountain."