Deuteronomy 16:4
And there shall be no leaven seen with thee in all thy borders seven days; neither shall any of the flesh, which thou sacrificedst at even on the first day, be left over night until the morning. --
Exodus 12:10
And ye shall let none of it remain until the morning; and what remaineth of it until the morning ye shall burn with fire.
Exodus 34:25
Thou shalt not offer the blood of my sacrifice with leaven; neither shall the sacrifice of the feast of the passover be left over night until the morning.
Exodus 13:7
Unleavened bread shall be eaten the seven days; and leavened bread shall not be seen with thee, neither shall there be leaven seen with thee in all thy borders.
Exodus 12:15
Seven days shall ye eat unleavened bread: on the very first day ye shall put away leaven out of your houses; for whoever eateth leavened bread from the first day until the seventh day that soul shall be cut off from Israel.
Exodus 12:8
And they shall eat the flesh in that night, roast with fire, and unleavened bread; with bitter herbs shall they eat it.