TSK · Exodus 34:25

They will eat the meat the same night; they will eat it roasted over the fire with bread made without yeast and with bitter herbs.

You will not eat anything made with yeast; in all the places where you live you must eat bread made without yeast.’”

If any of the meat from the consecration offerings or any of the bread is left over until morning, then you are to burn up what is left over. It must not be eaten, because it is holy.

They must not leave any of it until morning, nor break any of its bones; they must observe it in accordance with every statute of the Passover.

Clean out the old yeast so that you may be a new batch of dough– you are, in fact, without yeast. For Christ, our Passover lamb, has been sacrificed.