Exodus 19:10-14 ▼

10 The LORD also said to Moses, “Go to the people and consecrate them today and tomorrow [that is, prepare them for My sacred purpose], and have them wash their clothes

11 and be ready by the third day, because on the third day the LORD will come down on Mount Sinai [in the cloud] in the sight of all the people.

12 You shall set barriers for the people all around [the mountain], saying, ‘Beware that you do not go up on the mountain or touch its border; whoever touches the mountain must be put to death.

13 No hand shall touch him [that is, no one shall try to save the guilty party], but the offender must be stoned or shot through [with arrows]; whether man or animal [that touches the mountain], he shall not live.’ When the ram’s horn sounds a long blast, they shall come up to the mountain.”

14 So Moses went down from the mountain to the people and sanctified them [for God’s sacred purpose], and they washed their clothes.