Exodus 19:14

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;

13 a hand cometh not against him, for he is certainly stoned or shot through, whether beast or man it liveth not; in the drawing out of the jubilee cornet they go up into the mount.`

14 And Moses cometh down from the mount unto the people, and sanctifieth the people, and they wash their garments;

15 and he saith unto the people, `Be ye prepared for the third day, come not nigh unto a woman.`

16 And it cometh to pass, on the third day, while it is morning, that there are voices, and lightnings, and a heavy cloud, on the mount, and the sound of a trumpet very strong; and all the people who [are] in the camp do tremble.

17 And Moses bringeth out the people to meet God from the camp, and they station themselves at the lower part of the mount,