Of the many symbolic meanings of chametz (leaven), one of the best known is haughtiness, an inflated ego. An early source for this idea is the Sefer ha-Chinukh’s discussion of Mitzvah 117—which is, interestingly, not one of the commandments of Pesach, but the general prohibition of leaven in grain-offerings. Dough raises itself up in the course of leavening; this prohibition, writes the Chinukh, hints at God’s contempt for an attitude of self-exaltation. Abstaining from chametz, whether in preparing a grain offering or in observing Pesach, symbolizes striving for humility.
The Talmud (Pesachim 35a) teaches that only those grains that can be used to make matzah—wheat, barley, oats, rye and spelt—are subject to the Biblical prohibition of chametz. Taking the Chinukh’s interpretation a step further, we may suggest that these five grains’ capacity to become chametz symbolizes having a “capacity” for haughtiness, in the sense of having ample reasons to feel proud; matzah represents a person who, despite having such reasons, avoids succumbing to egotism.
In his classic letter to his son on the paramount importance of humility, known as Iggeret ha-Ramban, the Ramban argues that nothing that one has can justify a prideful attitude:
In what should a person’s heart take pride? If in wealth, “The Lord impoverishes and enriches” (I Samuel 2:7). If in honor—is that not God’s, as it is said: “Riches and honor come from You” (I Chronicles 29:12); and how could one adorn himself in his Master’s honor? And if one takes pride in his intellect, “He removes speech from the assured, and takes away the reason of sages” (Job 12:20). Indeed, all are the same before the Lord; for in His anger He lowers the proud, but through His favor he raises the lowly. Therefore lower yourself and the Omnipresent will lift you up.
The matzah, made from a grain with the potential for leavening, reminds us that although our possessions, talents, and successes may incline us to feel pride, we can maintain a proper, humble perspective by attributing all that we have to God.