Leviticus 16:29-31

29“This is to be a permanent statute for you: In the seventh month, on the tenth day of the month you are to practice self-denial and do no work, both the native and the alien who resides among you.

30Atonement will be made for you on this day to cleanse you, and you will be clean from all your sins before the Lord.

31It is a Sabbath of complete rest for you, and you must practice self-denial; it is a permanent statute.