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Pesachim 45


QUESTION: The Mishnah discusses the amount of Chametz which one is obligated to destroy. If there is a k'Zayis of Chametz in the crevices of a kneading basin ("Areivah"), one is Chayav to get rid of that Chametz. If there is *less* than a k'Zayis in the basin's crevices, one is not obligated to get rid of that Chametz because it is Batel. The Gemara explains that half of a k'Zayis of dough is Batel if it is either on the *bottom* of the basin or on the *middle part of the inside of its walls*. If, however, the Chametz is on the rim or on the *top of the inside of its walls* or on the *outside of the walls*, then even a half of a k'Zayis must be destroyed and is not Batel to the basin (see RASHI, DH Ela).

The Gemara continues and says that if there are two half k'Zaysim on the inside walls of the basin and they are not connected at all (by a thread of dough), then they are both Batel. Ula adds that this leniency applies only with regard to Chametz in the crevices of a basin. In a *house*, though, two half k'Zaysim must be disposed of even if they are not connected. The reason is because perhaps while sweeping the house, one will sweep the two separate half k'Zaysim into one pile, combining them together to form a full k'Zayis in one place.

Why does the Gemara need to add this reason to explain why two half k'Zaysim of Chametz in a house must be disposed of? The Gemara just taught that even if the two half k'Zaysim would be on the outside of the walls of the *basin*, they would not be Batel to the basin and one would be Chayav to get rid of them! Certainly, then, when they are on the floor of the house, they are not Batel to anything, and thus each half of a k'Zayis by itself must be destroyed!


(a) The MAHARAM CHALAVAH says that in a house, we might have thought that small pieces of Chametz that are less than a k'Zayis do not have to be disposed of, because of the Halachah of "Pirurin" (6b) which says that small crumbs of Chametz are insignificant and Batel. In the kneading basin, though, such small pieces of dough are still in good, usable condition, and thus they are still significant and are not Batel. The Gemara concludes that even in a house, small pieces of dough are not Batel because they might combine together to make a k'Zayis when one sweeps the house. Since they might get joined together and become significant, they are not Batel even when they are separate. When the Gemara earlier (6b) said that small crumbs are Batel, it was referring to dried crumbs that will never become fit, or -- as the PISKEI RI'AZ explains -- it is referring to very small crumbs which we do not fear will join together to become a k'Zayis. The MAGEN AVRAHAM (OC 442:2) gives the same explanation.

Similarly, RABEINU DAVID answers that small pieces are normally Batel and it is only when they are on a kneading basin that we say they are not Batel because they might join together. That is, on the outside of the basin itself they must be disposed of because of the concern that they might come in contact with each other and form a k'Zayis amount of Chametz. The Gemara concludes that a house is the same as the outside of the basin (and we do not say that in the house they are Batel because they are so far apart from each other).

(b) The MAGID MISHNAH (Hilchos Chametz u'Matzah 2:16) infers from the Rambam that the Halachah that half of a k'Zayis on the floor of a house must be disposed of applies only when the Chametz is not within the floor boards. If the Chametz pieces are between the floor boards and serve to fill up cracks in the floor, then they are Batel, just like the pieces of dough on the inside of the kneading basin which serve a purpose for the basin and thus are Batel.

(c) The RAMBAN (Milchamos) and RABEINU DAVID say that according to the RIF,this Gemara holds like Rav Huna who, earlier, did not reconcile the two conflicting Beraisos by saying that one is referring to places in the kneading basin which are "Makom Lishah" and the other is referring to places which are not "Makom Lishah." Rather, Rav Huna explained that the two Beraisos are arguing; one holds that a half k'Zayis on the inside of the wall of the basin is Batel, while the other holds that it is not Batel and must be destroyed. This Gemara (Rav Nachman) -- which discusses a half k'Zayis on the floor of a house -- is in accordance with the Beraisa that says that half of a k'Zayis is Batel even when it is not serving any other purpose. Therefore, the Gemara has to teach that this is not so in a house, and a half k'Zayis in a house is *not* Batel because it might be swept together with another half k'Zayis to form a whole k'Zayis.

(d) TOSFOS (45a, DH Kan) has a different explanation of "Makom Lishah." Tosfos says that when pieces of dough are *not* in "Makom Lishah," we are more lenient, and not more stringent, and we say that it is Batel, because the dough that one is kneading in the basin will not come into contact with it and there is no concern that it will get mixed in with the Matzah and be eaten. Therefore, a half k'Zayis on the floor of a house will certainly be Batel (if not for the reason that they might be swept into one pile to form a k'Zayis).

(e) RABEINI YECHIEL cited by TOSFOS RABEINU PERETZ suggests that small pieces of Chametz are Batel not because of the Halachah of Pirurin (6b), but because they are a half of a Shi'ur ("Chatzi Shi'ur"), and the Isur of Bal Yera'eh does not apply to Chametz less than the minimum Shi'ur (a k'Zayis). The TESHUVOS P'NEI YEHOSHUA (#15) also gives this answer. However, if so, why should a half k'Zayis not be Batel when it is on the rim or on the outside of the kneading basin? The P'nei Yehoshua concludes that it must be that the basin being discussed has a lot of pieces of Chametz around its outside, which all add up to a k'Zayis. Therefore, they must be disposed of because the basin joins them all together. However, if there were multiple pieces of a half k'Zayis of Chametz on the floor of a house, it is not necessary to dispose of them because there is nothing to join them together to be a k'Zayis. Therefore, it is necessary to give the reason that one might sweep them together. This is also the way the KORBAN NESANEL (3:2:100) learns the Gemara.

According to this explanation, we need to understand why one does not transgress the Isur of Bal Yera'eh with half of a Shi'ur. We know that Chatzi Shi'ur is Asur mid'Oraisa (as the Gemara (Yoma 74a) teaches with regard to eating on Yom Kippur). Why is our Gemara assuming that Chatzi Shi'ur is not Asur? The CHACHAM TZVI (#86) explains that Chatzi Shi'ur is only Asur when it comes to Isurei Achilah -- forbidden food items. By eating the item, no matter how small it is, one gives it importance and therefore it is Asur.

Alternatively, the SHA'AGAS ARYEH (#81) explains, the Isur of Chatzi Shi'ur does not apply to Bal Yera'eh for the following reason. Why is it Asur to eat Chatzi Shi'ur of an Isur? The Gemara in Yoma says it is Asur because the small amounts of food are "Chazi l'Itzterufi," they join together to become a proper Shi'ur. This may mean that it is Asur to eat one half-Shi'ur because if the person eats another half-Shi'ur, he will have eaten an entire Shi'ur and will have transgressed the Isur d'Oraisa *retroactively* by eating the first half-Shi'ur. Anything which can turn into an Isur retroactively, is Asur. When it comes to Bal Yera'eh and Bal Yimatzei, though, even if one had at the beginning of Pesach one half k'Zayis in his possession, and then later during Pesach another half k'Zayis came into his possession, he will only be in violation of Bal Yera'eh and Bal Yimatzei at the point in time at which he has a full Shi'ur in his house at once. The act of having the first half-Shi'ur alone can *never* be Asur, because no matter what one buys afterwards, he has not transgressed anything *until* he buys another half-Shi'ur (since at that point he has an entire Shi'ur in his possession).

Many Acharonim reject the logic of this assertion, because Bal Yera'eh should be Asur even with Chatzi Shi'ur for several reasons. (1) The MINCHAS CHINUCH (11:12) says that even though that logic works to explain why there is no Isur d'Oraisa of Chatzi Shi'ur for Bal Yera'eh, but mid'Rabanan, at least, there should be an Isur of Chatzi Shi'ur. (2) The MAHARAM CHALAVAH writes that we know that the prohibition of Bal Yera'eh, of not having Chametz in one's possession, is in order to prevent one from eating Chametz on Pesach. Consequently, even if the Isur of Chatzi Shi'ur applies only to Achilah, the Shi'ur of Bal Yera'eh is based on the Shi'ur of Achilah, and therefore Chatzi Shi'ur should be Asur mid'Oraisa for Bal Yera'eh just like it is for Achilah (see also TAZ OC 442:5).

The Gemara explains that one is obligated to dispose of crumbs of Chametz that are in one's home even when they are less than the size of a k'Zayis. How intensive does a person's Bedikas Chametz have to be?

The ROSH here, instead of writing the Halachos discussed in the Gemara about the small amounts of Chametz that are in the kneading basin, writes that it is not important to discuss all of the intricacies of the Halachah, because "Yisrael Kedoshim Hem" -- the Jews are a holy nation, and their practice is to be stringent and to rub of any possible traces of Chametz from the walls of their homes and from the chairs and the like. The Rosh cites support to this practice from the Yerushalmi that states that even Chametz that was made as part of the floor must be destroyed unless it is not fit for animal consumption.

In practice, many Jewish homes follow this custom to clean and dispose of any possible traces of Chametz in their houses. However, the Torah sages have emphasized that during the weeks and days leading up to Pesach, one should make sure that the members of his family, especially his wife, do not ruin their enjoyment of the Yom Tov due to working excessively hard.

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