There should be no yeast in your houses for seven days. Whoever eats anything with yeast in it must be excluded from the community of Israel, whether he is an Israelite or not.
“Never offer the blood of a sacrifice to me at the same time you offer anything containing yeast. No part of the sacrifice at the Passover Festival should be left over in the morning.
He used another illustration. “The kingdom of heaven is like yeast that a woman mixed into a large amount of flour until the yeast worked its way through all the dough.”