Deuteronomy 16:3 in the King James Version
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.
Context
2 You shall sacrifice the Passover to the LORD your God, of the flock and the herd, in the place which the LORD shall choose to cause his name to dwell there.
3 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.
4 No yeast shall be seen with you in all your borders seven days; neither shall any of the meat, which you sacrifice the first day at evening, remain all night until the morning.