[Ha-Rav's commentary on the Haggadah]
Question: What is the connection between freedom and the prohibition of Chametz (leaven)? The entire process of ridding ourselves of Chametz seems like a heavy burden which robs a person of his freedom. And in general, all of the Mitzvot seem to deprive the natural movements of a person.
Answer: Rav Kook explained that true freedom includes two aspects:
a. Freedom of the body: Physical freedom from any foreign subjugation: Anything which forces the image of G-d within a person to be subjugated to any other power lessens that person’s worth.
b. Freedom of the soul: Spiritual freedom from anything which turns it from the straightness which is its essential existence. G-d created man upright, and He cleanses man from any inner refuse which sullies his inner holiness.
Regarding these two aspects, each morning we recite the blessing, "who has not made me a slave." The Mitzvot are not foreign entities which are forced upon a person, rather they reveal his inner essence. Before the Mitzvot were engraved on the tablets that were given at Mount Sinai, they were written on the “tablets” of every Jew's soul. Our Sages therefore said: They were "Charut" (engraved) on the tablets – do not read the word as "Charut" (engraved) but as "Cherut" (freedom) (Pirkei Avot 6:2). By slightly changing the vocalization of the word, we learn an incredible lesson: In order to truly be a free people, it is not enough to be liberated from physical slavery. On the contrary, it is possible to have an enlightened slave whose spirit is full of freedom, and a free person whose spirit is enslaved. We were transformed into free people on Pesach, but we do not become truly free until we rid ourselves of anything which robs us of our natural essence. This is the reason for destroying the Chametz. It symbolizes the evil inclination and called "the yeast in the dough," because it ferments in the heart of people and causes them to transgress (see Bereachot 17a). The destruction of our internal Chametz is what allows us to raise the flag of freedom (Olat Re'eiyah vol. 2, pp. 244-245).