Leviticus 23:5

³  Six days shall work be done: but the seventh day is the sabbath of rest, an holy convocation; ye shall do no work therein: it is the sabbath of the LORD in all your dwellings.

⁴  These are the feasts of the LORD, even holy convocations, which ye shall proclaim in their seasons.

⁵  In the fourteenth day of the first month at even is the LORD's passover.

⁶  And on the fifteenth day of the same month is the feast of unleavened bread unto the LORD: seven days ye must eat unleavened bread.

⁷  In the first day ye shall have an holy convocation: ye shall do no servile work therein.