The Talmud in tractate Berachoth (17a) poses the question why it is forbidden to eat or even to possess chametz, i.e. leaven, such as bread, on Pesach. What is there in the nature of leaven that it should be forbidden on Pesach? And why is matza the most desirable food for Pesach?
Instead of providing us with a straight answer, the Talmud responds by asking still another question. Why do people sin altogether? Understanding that people will continue to transgress, the Talmud tries to analyze the paradoxical situation in which many people find themselves: man's desire to do well, and his constant encounter with his/her evil inclination. Realizing that this inclination is difficult to overcome, it suggests that human beings, especially Jews, should make the following declaration whenever they try to obey the laws of the Torah but fail to do so:
"Lord of the Universe
It is well known to You that it is our desire to do Your will
But what prevents us?
The yeast in the dough."
The expression: "The yeast in the dough" is well known in the Talmud. It is the description for the evil impulse in human beings. The last is the one which is responsible for "all ferment in the human heart" and why man does not always behave the way he should.
We now understand the circuitous answer the Talmud provides to the original question concerning the reasons why it is forbidden to possess or consume leaven on Pesach. Leaven is after all used to cause the yeast in the dough to rise and in a literal sense it is exactly that which also causes bread to become bread which is forbidden on Pesach. In other words: It is the most distinct symbol of the cause of all human transgressions!
This however begs the question. Why is the evil inclination symbolized by leaven? What does leaven do wrong that it should be used as the symbol for the evil urge in man?
A closer look however reveals a most fascinating idea.
Bread, chametz, is blown up matza. It is matza which went overboard and got wild.
What after all, is the essential difference between both? They are made from exactly the same ingredients. It is only the speed which makes the difference between the two. If the dough is baked quickly you get matza. However if the dough is left for a while, it will rise and after being baked turns into bread.
The only real difference between the two is therefore hot air. An ingredient of no real substance!
And it is this substance which makes bread look powerful in comparison to matza. It rises, becoming haughty, giving the impression that it consists of a great amount of substance and abundance while in reality it mainly consists of hot air. The matza however is humble; there is no attempt to make more of itself than what it really contains: plain dough.
Bread then is an arrogant matza. And it is for this reason that it symbolizes the evil inclination since it is the attitude of haughtiness, blowing oneself up beyond one's real self which leads to undesirable acts which causes man to go astray. It is the source of all transgressions. Would a human being be humble, he or she would not contemplate doing anything wrong. Only arrogance leads man to undesirable deeds.
On Pesach, which symbolizes the beginning of the Jewish people, Jews are once more reminded that their mission to become a light unto the nations can only start in the spirit of humility. Arrogance can never be the foundation of spirituality and moral integrity. It cannot inspire others, nor will it have a lasting effect.
Consequently the art achieving real life is to be like a matza in a world of chametz.
This is the reason, as understood by the Talmud, why one is prohibited to possess or eat chametz on Pesach. Only the matza is food of moral quality.
The question the readers now need to ask is why we are allowed to eat bread throughout the rest of the year and even use it in the Temple? For an answer see: Talmud Yoma 69b.
May God allow us to serve Him in this spirit and grant us and the world the final redemption.
Chag Kasher VeSameach