Exodus 19:10-12

Young's Literal Translation

¹⁰ And Jehovah saith unto Moses, `Go unto the people; and thou hast sanctified them to-day and to-morrow, and they have washed their garments,

¹¹ and have been prepared for the third day; for on the third day doth Jehovah come down before the eyes of all the people, on mount Sinai.

¹² `And thou hast made a border [for] the people round about, saying, Take heed to yourselves, going up into the mount, or coming against its extremity; whoever is coming against the mount is certainly put to death;