Lev Leviticus, chapter Book of Leviticus, chapter 23
You2f shall do no manner of work: [it shall be] a statute forever throughout your generations in all your dwellings.
It [shall be] unto you a Shabbat [Rest] of rest, and you2f shall afflict your souls: in the ninth [day] of the month at even, from even unto even, shall you2f celebrate your Shabbat [Rest].Lev 16:31