This threat was given before, Exodus 12:15. So infinitely important, in the sight of God, is the unleavened, unmingled sacrifice of Jesus.
Related Commentaries of Exodus 12:19
Exodus 12:19
19 Seven days shall there be no leaven found in your houses: for whosoever eateth 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.