Exodus 19:12

19:12 You must set boundaries for the people all around, saying, ‘Take heed to yourselves not to go up on the mountain nor touch its edge. Whoever touches the mountain will surely be put to death!

Exodus 34:3

34:3 No one is to come up with you; do not let anyone be seen anywhere on the mountain; not even the flocks or the herds may graze in front of that mountain.”