Leviticus 16:29-31

29This is to be a permanent statute for you: On the tenth day of the seventh month, you shall humble yourselves1 and not do any work—whether the native or the foreigner who resides among you— 30because on this day atonement will be made for you to cleanse you, and you will be clean from all your sins before the LORD. 31It is a Sabbath of complete rest for you, that you may humble yourselves; it is a permanent statute.