Parsha Mitzvot: Bo: Mitzvah 22 – Concept 110
“Moses said to the people, ‘Remember this day on which you departed from Egypt from the house of bondage, for with a strong hand, God removed you from here, and therefore Chametz may not be eaten.” (Exodus 13:3) We are forbidden to eat Chametz all seven days of Pesach. (Rambam, Hilchot Chametz U’Matzah)
The verse simply wants to tell us that Chametz is a symbol of the Attribute of Justice – the “Strong Hand.” Seeing that it was necessary for Israel to invoke God’s attribute of Justice against the Egyptians in order for them to be redeemed, God forbade them the consumption of Chametz at the time we commemorate the Exodus so that we would steer clear of putting our faith in the attribute of Justice as an attribute that acts on its own.
Were we to do this, we would be guilty of heresy. It would have been easy to conclude that God invoked only the attribute of Justice as both He and His Heavenly Tribunal cooperated in the downfall of the Egyptians. (Rabbeinu Bachya)