Exodus 19:23

Moses said to the Lord, “The people cannot come up to Mount Sinai, for You warned us, saying, ‘Set bounds about the mountain and consecrate it.’”

Exodus 19:12

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.

Joshua 3:4-5

However, there shall be between you and it a distance of about 2,000 cubits by measure. Do not come near it, that you may know the way by which you shall go, for you have not passed this way before.”

Treasury of Scripture Knowledge

Summary

And Moses said unto the LORD, The people cannot come up to mount Sinai: for thou chargedst us, saying, Set bounds about the mount, and sanctify it.

Bible References

Set bounds

Exodus 19:12
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.
Joshua 3:4
However, there shall be between you and it a distance of about 2,000 cubits by measure. Do not come near it, that you may know the way by which you shall go, for you have not passed this way before.”