The prohibition against ĥametz on Pesaĥ is especially stringent, for the Torah not only forbade eating it, but commanded that it not be seen nor found in our possession. Our Sages further forbade eating any food with even the slightest amount of ĥametz mixed in. Thus the avoidance of ĥametz on Pesaĥ is absolute. This is because ĥametz symbolizes evil, as it says in the Zohar (2:40b) that ĥametz is the evil impulse. Specifically, it alludes to the impulse of pride. Fermentation causes dough to rise – it looks as though the dough is inflating itself and puffing up with pride, as an arrogant person would. In contrast, matza, which remains in its original size, as it was when God created it, symbolizes the trait of humility.
At first glance, this is difficult to understand. If ĥametz represents the evil inclination, then why is there no commandment or custom to avoid it throughout the year? On the contrary, man is praised for knowing how to make wheat into tasty ĥametz cakes (see Tanĥuma Tazri’a 5). This was the Creator’s purpose in endowing man with the wisdom and practical skills to engage in developing the world. God created an imperfect world intentionally, so that man could imitate His deeds and participate in improving the world through scientific and technological development.
The answer is that there are two types of pride: One is that man exaggerates his own praiseworthiness and thinks he is wiser, stronger, and better than he really is. Any intelligent person understands that such pride harms one’s ability to actualize his potential for the betterment of the world. His ability to judge is completely impaired, and he cannot conduct his life properly. Clearly, such pride is inappropriate all year long and has nothing to do with the prohibition of ĥametz. On the contrary, such pride detracts from one’s good works and thus harms the good, year-round ĥametz.
The second type of pride, which corresponds to ĥametz on Pesaĥ, is man’s pride vis-à-vis his Creator, his God. Jewish faith is predicated on the acknowledgment that God created the world and determined its destiny, and that the roots of all things depend on Him alone. Although God gave man the ability to improve and to develop the world, this is limited to manipulating and developing the outgrowths of the root elements of creation; man has no power over the root elements, which are divine creations. God created the world, chose the people of Israel to be His am segula, His treasured nation, and gave them the Torah. Man has no authority to call these fundamental principles into question. Therefore, when one stands before his Creator, he must envelop himself in humility and make every effort not mix his petty human thoughts with the fundamental principles of creation. Such confusion, like ĥametz on Pesaĥ, is forbidden.
Pesaĥ, and especially the Seder, is designed to instill in us the fundamentals of faith: that the world has a Creator, that He watches over His creatures, and that He chose the people of Israel to reveal His name in the world. Whenever there is revelation of an aspect of the divine in the world, it appears in a completely miraculous fashion, to show that it is not a human endeavor. Thus, the Exodus was accompanied by signs and wonders, to make public that the election of Israel was a divine matter. Similarly, the Torah was given with obvious miracles, to a generation that lived miraculously for forty years in the desert, in order to make it known that this was an entirely divine matter. In other words, we receive the fundamental principles of faith from God – we do not invent them. Whoever mixes some human aspect into these basic principles of faith is guilty of idolatry. This is alluded to in Zohar’s statement that ĥametz on Pesaĥ is idolatry (2:182a).
Therefore, on Pesaĥ, the holiday geared toward imparting the fundamentals of faith, we are commanded to be extremely cautious to avoid eating and possessing even a smidgen of ĥametz, which symbolizes our human aspects that must not get mixed in when we speak about the roots and foundations of faith. During the rest of the year, however, when we are involved with developing and improving the branches, ĥametz is allowed and even desirable.