Exodus

And thou shalt set bounds unto the people round about, saying, Take heed to yourselves, that ye go not up into the mount, or touch the border of it: whosoever toucheth the mount shall be surely put to death:

The chariots of God are twenty thousand, even thousands of angels: the Lord is among them, as in Sinai, in the holy place.

Yet there shall be a space between you and it, about two thousand cubits by measure: come not near unto it, that ye may know the way by which ye must go: for ye have not passed this way heretofore.

And Joshua said unto the people, Sanctify yourselves: for to morrow the Lord will do wonders among you.