Leviticus 23:1-8

The LORD spoke to Moses: “Speak to the Israelites and tell them, ‘These are the LORD’s appointed times which you must proclaim as holy assemblies – my appointed times: “‘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. “‘These are the LORD’s appointed times, holy assemblies, which you must proclaim at their appointed time. In the first month, on the fourteenth day of the month, at twilight, is a Passover offering to the LORD. Then on the fifteenth day of the same month will be the festival of unleavened bread to the LORD; seven days you must eat unleavened bread. On the first day there will be a holy assembly for you; you must not do any regular work. You must present a gift to the LORD for seven days, and the seventh day is a holy assembly; you must not do any regular work.’”