Negative Commandment #3
Sefer Ha’mitzvos Ha’Katzar (The concise book of mitzvos)
By the Chofetz Chaim
This book lists the Torah mitzvos that can be observed today
Second Section – the Negative Commandments
3. It is a negative commandment not to find any chametz (bread products) in a Jew's possession [on Passover]
as it states in Shemos (Exodus) 12:19, "Seven days, leavened items should not be found in your houses." A person that leaves chametz in his house on Passover, for example, leaving dough to rise in his house during Passover, or buying chametz and placing it in one's house knowingly, gets lashes twice (because of the commandments "it shall not be seen" and "it shall not be found") because he has done an action. But one that leaves chametz in his house from before Passover and does not remove it, has transgressed the two commandments mentioned, but does not receive lashes, because there was no action involved. Regarding a non-Jew's chametz found in a Jew's property, if the Jew takes responsibility for it, he is required to remove it. If the Jew does not take responsibility for it, he is not transgressing this commandment, as it states in Shemos 13:7, "You shall not see for yourself..." This means yours, you shall not see, but you can see others. If the non-Jew can take the Jew to a non-Jewish court because of the chametz, even if the Jew did not accept responsibility, the Jew is required to remove the chametz.
Chametz that remained in a Jew's possession during Passover is forbidden to derive benefit from, according to the law of the Sages, as a punishment. This is because of the transgression of the commandments not to see it and not to find it. It is forbidden even if they were accidentally forgotten.
This applies in all places and at all times for men and women.