Deuteronomy 16:3-4

MKJV(i) 3 You shall eat no leavened bread with it. Seven days you shall eat unleavened bread with it, the bread of affliction, for you came forth out of the land of Egypt in haste, so that you may remember the day that you came forth out of the land of Egypt all the days of your life. 4 And there shall be no leavened bread seen with you in all your borders for seven days. Nor shall any of the flesh which you sacrificed in the first day at evening remain all night until the morning.