Leviticus 23:3-6
English Standard Version
4"These are the appointed feasts of the Lord, the holy convocations, which you shall proclaim at the time appointed for them.
5In the first month, on the fourteenth day of the month at twilight, is the Lord 's Passover.
6And on the fifteenth day of the same month is the Feast of Unleavened Bread to the Lord; for seven days you shall eat unleavened bread.