Leviticus 23:3-6

³Six days shall work be done: but on the seventh day is a sabbath of solemn rest, a holy convocation; ye shall do no manner of work: it is a sabbath unto Jehovah in all your dwellings.

⁴These are the set feasts of Jehovah, even holy convocations, which ye shall proclaim in their appointed season.

⁵In the first month, on the fourteenth day of the month at even, is Jehovah’s passover.

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