Bitul Chametz: The Rambam's Revolutionary Understanding of Possession and Nullification

Full Summary

This shiur presents a revolutionary understanding of the Rambam (רמב"ם)'s approach to bitul chametz (nullification of leavened bread) that fundamentally differs from other Rishonim. The central focus is on resolving the apparent contradiction in the Kesef Mishneh's version of the Rambam regarding when bitul works versus when one must physically destroy chametz. The Rambam distinguishes between chametz yadu'a (known chametz) and chametz ein yadu'a (unknown chametz), ruling that known chametz requires destruction while unknown chametz can be nullified. A major chiddush emerges from the Rambam's reading of the Gemara (גמרא)'s case of 'shema yimtza galus ki yafa' (perhaps he will find a loaf of bread). Unlike Rashi (רש"י) and Tosafot who understand this as a case where one is automatically over bal yera'eh upon finding chametz, the Rambam holds that if one properly performed bedikat chametz and bitul, finding chametz on Pesach (פסח) does not create a violation of bal yera'eh bal yimatzei. The key insight is that chametz found after proper bedika is considered 'eino shelcha' (not yours) - the Torah (תורה) only puts chametz back into one's possession to create liability when they failed to fulfill their obligations. The shiur analyzes the specific case in the Gemara where someone planned to burn chametz before Pesach but forgot to do so. In this case, since they failed to properly dispose of known chametz, they become liable for bal yera'eh from the moment of the prohibition. The Rambam's reading explains why bitul cannot help once chametz is found - not because of the general rule that bitul doesn't work on chametz yadu'a for tashbisu, but because once one violates bal yera'eh, the Torah considers the chametz as being in their possession. A crucial distinction emerges regarding the timing of bitul. According to this interpretation, when one performs bitul during bedikat chametz at night, the bitul is not effective immediately but rather becomes effective at the time of the prohibition (sha'as issur) in the morning. This explains why the Gemara asks why not perform bitul in the morning - because the bitul's effectiveness is timed for sha'as bier anyway. The analysis reveals that according to the Rambam, most cases of finding chametz on Pesach do not result in bal yera'eh violations. Only when someone knew about chametz and failed to dispose of it (either through burning or proper bitul) do they become liable. This transforms our understanding of chametz ownership on Pesach and the mechanics of bitul, showing that the Rambam's system is fundamentally different from other Rishonim who assume automatic liability upon finding chametz. The shiur concludes by noting that this interpretation resolves the apparent contradictions in the Rambam's rulings while revealing a sophisticated understanding of possession, nullification, and religious obligation that differs markedly from the approaches of Rashi, Tosafot, and other major commentators.