Leviticus 23:2-4

2“Speak to the Israelites and tell them, ‘These are the Lord’s appointed times which you must proclaim as holy assemblies – my appointed times:

3“‘Six days work may be done, but on the seventh day there must be a Sabbath of complete rest, a holy assembly. You must not do any work; it is a Sabbath to the Lord in all the places where you live.

4“‘These are the Lord’s appointed times, holy assemblies, which you must proclaim at their appointed time.