Leviticus 23:3, 32

“ ‘There are six days when you may work, but the seventh day is a day of sabbath rest, a day of sacred assembly. You are not to do any work; wherever you live, it is a sabbath to the LORD.

It is a day of sabbath rest for you, and you must deny yourselves. From the evening of the ninth day of the month until the following evening you are to observe your sabbath.”