This mitzvah forbids chametz from being found in one’s possession during the seven days of Passover. Unlike the previous mitzvah, which prohibits chametz being seen, this prohibition is broader — even hidden chametz or chametz stored away is forbidden. To fulfill this mitzvah, Jews must destroy or nullify chametz before the festival begins, ensuring complete disassociation from it. Our Sages stated explicitly in a number of places, "One transgresses, 'It may not be seen,' and 'It may not be found.'". The laws of these two mitzvos are explained in the beginning of tractate Pesachim. There it is also explained which things are prohibited by the verse, "It may not be seen...in all your territories" and which are prohibited by the verse, "It may not be found in your homes".

Commentary & Classical Explanation:

• Rambam (Hilchot Chametz U’Matzah 2:2): Teaches that possession of chametz during Pesach, whether seen or unseen, is a Torah violation.
• Sefer HaChinuch (Mitzvah 14): The root is to eliminate chametz entirely, reinforcing the symbolic message of humility and dependence on Hashem, represented by matzah.
• Talmud (Pesachim 5b–6a): Distinguishes between “bal yera’eh” (not to be seen) and “bal yimatzei” (not to be found), emphasizing the Torah’s double prohibition.