Leviticus 23:1-3

The LORD spoke again to Moses, saying, “Speak to the children of Israel and say to them, ‘The appointed times (established feasts) of the LORD which you shall proclaim as holy convocations—My appointed times are these: ‘For six days work may be done, but the seventh day is the Sabbath of complete rest, a holy convocation (calling together). You shall not do any work [on that day]; it is the Sabbath of the LORD wherever you may be.