Exodus 19:23

And Moses said to Yahweh, "The people are not able to go up to Mount Sinai, because you yourself warned us, saying, 'Set limits [around] the mountain and consecrate it.'"

Exodus 19:12

And you must set limits [for] the people all around, saying, 'Guard yourselves {against} going up to the mountain and touching its edge. Anyone touching the mountain will certainly be put to death.

Joshua 3:4-5

[But] there will be a distance between you and it of about two thousand cubits in measurement. Do not come near it, so that you may know the way that you must go, for you have not passed on [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
And you must set limits [for] the people all around, saying, 'Guard yourselves {against} going up to the mountain and touching its edge. Anyone touching the mountain will certainly be put to death.
Joshua 3:4
[But] there will be a distance between you and it of about two thousand cubits in measurement. Do not come near it, so that you may know the way that you must go, for you have not passed on [this] way {before}."