Deuteronomy 16:3 in the World English Bible
You shall eat no leavened bread with it. You shall eat unleavened bread with it seven days, even the bread of affliction (for you came out of the land of Egypt in haste) that you may remember the day when you came out of the land of Egypt all the days of your life.
Context
2 Thou shalt therefore sacrifice the passover unto the LORD thy God, of the flock and the herd, in the place which the LORD shall choose to place his name there.
3 Thou shalt eat no leavened bread with it; seven days shalt thou eat unleavened bread therewith, even the bread of affliction; for thou camest forth out of the land of Egypt in haste: that thou mayest remember the day when thou camest forth out of the land of Egypt all the days of thy life.
4 And there shall be no leavened bread seen with thee in all thy coast seven days; neither shall there any thing of the flesh, which thou sacrificedst the first day at even, remain all night until the morning.