Exodus 12:19,20
Seven days shall there be no leaven found in your houses: for whoever eats that which is leavened, even that soul shall be cut off from the congregation of Israel, whether he be a stranger, or born in the land.
Nave's Topical Index—AKJV

Exodus 13:3,4,7
And Moses said to the people, Remember this day, in which you came out from Egypt, out of the house of bondage; for by strength of hand the LORD brought you out from this place: there shall no leavened bread be eaten.
Nave's Topical Index—AKJV

Exodus 23:18
You shall not offer the blood of my sacrifice with leavened bread; neither shall the fat of my sacrifice remain until the morning.
Nave's Topical Index—AKJV