Exodus 19:10-12

King James Version

¹⁰ And the Lord said unto Moses, Go unto the people, and sanctify them to day and to morrow, and let them wash their clothes,

¹¹ And be ready against the third day: for the third day the Lord will come down in the sight of all the people upon mount Sinai.

¹² 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: