OPINIONS: Rava concludes that the Halachah follows the opinion of Rav, that
when Chametz gets mixed up with non-Chametz items on Pesach, we say that it
is Asur even if a minute amount of Chametz fell into the non-Chametz. During
Pesach, "Mashehu," any amount of Chametz, is Asur "Bein b'Mino, Bein she'Lo
b'Mino," whether it fell into its own type of food or into a different type
of food.
Why is the Isur of Chametz so much more stringent Halachically than all
other Isurim? All other Isurim are only Asur b'Rov, when the majority of the
mixture is the forbidden food, in a case of two like foods that were mixed
together, or "b'Nosen Ta'am," when enough of the forbidden food fell into
the permitted food so that its taste is noticeable in the mixture, if two
liquids were mixed together (this amount is defined, practically, as 1/60th;
see REMA, Yoreh Deah 98:1).
(a) RASHI (29b, DH she'Lo b'Mino) says that Rava rules like Rav, who holds
that for *all* Isurim, "Min b'Mino" is Asur b'Mashehu. The only difference
between Chametz and other Isurim is that Chametz is also Asur b'Mashehu when
it is "Min she'Lo b'Mino," when it falls into another type of food. Any
other Isur, when the mixture is "Min she'Lo b'Mino," is Asur only b'Nosen
Ta'am, while Chametz is Asur b'Mashehu. Rashi explains that the difference
is due to the severity of the Isur of Chametz. Transgressing the Isur of
Chametz is punishable with Kares, in addition people are not accustomed to
refraining from Chametz (11a), for they eat it throughout the year. Rav
therefore decreed that even a mixture of "Min she'Lo b'Mino" is Asur
b'Mashehu, like "Min b'Mino."
(b) TOSFOS (DH Amar Rava) argues with Rashi, who states that "Min b'Mino" of
all other Isurim is also Asur b'Mashehu. Tosfos asserts that "Min b'Mino" of
all other Isurim is not Asur b'Mashehu, but only b'Rov, which is the opinion
of the Rabanan. The reason why Chametz, even "Min b'Mino," is Asur b'Mashehu
is because of the severity of the Isur of Chametz, as Rashi explained.
Because of the severity of the Isur, the Rabanan decreed that *both* "Min
b'Mino" and "Min she'Lo b'Mino" are Asur b'Mashehu.
(c) The RAMBAM (Hilchos Ma'achalos Asuros 16:9) and the RAN here say that
the reason Chametz is Asur b'Mashehu is because Chametz is a "Davar she'Yesh
Lo Matirin," it is something forbidden which will eventually become
permitted. Since one could wait until after Pesach and then eat the mixture,
it is therefore Asur b'Mashehu on Pesach. Rava rules like Rebbi Shimon who
holds that Chametz is only Asur mid'Rabanan after Pesach. When the Chametz
is mixed with another food, the Rabanan did not apply their decree and it is
Mutar. Therefore, since one can wait until after Pesach when the mixture
will be Mutar, on Pesach it is Asur b'Mashehu.
The RAN casts doubt on this reasoning. Even though a *mixture* of Chametz is
Mutar after Pesach, Chametz that is distinct and not mixed is indeed
prohibited (mid'Rabanan) after Pesach is over. Therefore Chametz cannot be
called a "Davar she'Yesh Lo Matirin."
The MORDECHAI (Pesachim #553) suggests another reason why Chametz is not
considered a "Davar she'Yesh Lo Matirin." Since the Chametz will become Asur
at a later time (i.e. next Pesach), its Heter is not indefinite and it
cannot be called a "Davar she'Yesh Lo Matirin."
(d) RABEINU TAM (in Tosfos DH Amar Rava) and the BA'AL HA'ME'OR do not have
the reading in the Gemara that Rava said that a mixture of Chametz is Asur
b'Mashehu, but rather merely that it is Asur. Rava means to say that it is
Asur "b'Nosen Ta'am," in accordance with the opinion of Rebbi Yochanan. If
so, there is no difference between Chametz and all other Isurim. This is
also the opinion of the SHE'ILTOS.
HALACHAH: The SHULCHAN ARUCH (OC 447:1) rules like Tosfos (see (b) above)
that mixtures of all other Isurim of "Min b'Mino" are only Asur "b'Nosen
Ta'am," while a mixture with Chametz (both "Min b'Mino" and "Min she'Lo
b'Mino") is Asur b'Mashehu, due to the severity of the Isur.
However, the MISHNAH BERURAH (447:2) adds that if there are other pressing
reasons that one needs to be lenient, he may rely on the She'iltos, (d)
above, and permit a mixture with Chametz as long as it is not "Nosen Ta'am."
Concerning the question whether Chametz is a "Davar she'Yesh Lo Matirin"
(see (c) above), both opinions are cited by the REMA (YD 102:4) and the
SHACH (YD 102:14).
There is a practical difference between these two reasons (the severity of
the Isur of Chametz, or the fact that Chametz is a "Davar she'Yesh Lo
Matirin") for forbidding mixtures of Chametz even b'Mashehu. If it is
because of the severity of the Isur of Chametz, then it is only Asur when
Kares applies. On Erev Pesach, after the sixth hour and before nightfall,
Chametz is Asur but there is no Kares. As a result, a mixture of "Min
b'Mino" will *not* be Asur b'Mashehu. This is how Tosfos would rule in such
a case. However, according to the Rambam, a mixture of Chametz on Erev
Pesach will also be Asur b'Mashehu, because it is a "Davar she'Yesh Lo
Matirin," which will become Mutar after Pesach. (MAGID MISHNAH, Hilchos
Chametz u'Matzah 1:5)
The SHULCHAN ARUCH (OC 447:2) rules that a mixture of Chametz on Erev Pesach
is Mutar if the quantity of Chametz is only a Mashehu. We see from this
ruling that the Shulchan Aruch does *not* agree with the Rambam and he holds
that Chametz is not a Davar she'Yesh Lo Matirin.