Exodus 19:9-11

Young's Literal Translation

⁹ And Jehovah saith unto Moses, `Lo, I am coming unto thee in the thickness of the cloud, so that the people hear in My speaking with thee, and also believe in thee to the age;' and Moses declareth the words of the people unto Jehovah.

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.