The Mixed Bag Dilemma
The flesh of a chatat sin offering is eaten by the kohanim while the flesh of an olah burnt offering is completely consumed by the fire of the altar. An interesting problem develops when parts of a chatat become mixed up with those of an olah. There is no simple solution to burn all of them because the Torah prohibited burning on the altar anything which has remained for eating after a part of it has already been offered on the altar. Since the fatty innards of the chatat have already been offered on the altar the remaining flesh cannot be offered. The need to burn the olah parts and the restriction on burning the chatat parts thus create a halachic impasse.
Rabbi Elazar, however, came up with a solution. The ban on burning the chatat flesh is derived from the passage (Vayikra 2:11) which, in issuing the ban on offering leavened products or honey on the altar, uses a phrase which hints at a ban on offering anything from which a part has already been offered for burning. In the following passage, however, the Torah reiterates this ban by stressing that "they shall not be offered as a satisfying aroma". Rabbi Elazars conclusion is that the ban on offering the flesh of the chatat applies only when the intention is to offer it as a sacrifice "a satisfying aroma" for G-d since G-d directed that it not be used for that purpose. If we view the chatat flesh as mere wood to fuel the fire of the altar, he contends, this ban does not apply. It is therefore possible to place this mixed bag of olah and chatat parts on the fire of the altar and to view the latter as mere fuel rather than an offering.
A Clash of Tastes
One of the most remembered features of the Pesach Seder, the "Hillel Sandwich", is mentioned in our gemara in reference to the issue of whether different foods eaten together neutralize the taste of each other. The position of the Sage Reish Lakish is that if one eats three different kinds of forbidden foods mixed together he is not liable for punishment by lashes because it is inevitable that as he chews these foods a portion of one will be combined with a larger portion of another and its taste neutralized. Since we cannot ascertain which of these foods was dominant in the chewing process the warning we issued before eating in order to make him liable for lashes is considered a dubious warning which cannot bring lashes in its wake.
This position is challenged by Rabbi Elazar who states that just as foods eaten in the performance of a mitzvah do not neutralize each other so too do forbidden foods not neutralize each other. The Mishnaic Sage who states that mitzvah foods do not neutralize each other is identified as Hillel. During the time of the Beit Hamikdash when Jews ate the flesh of the Korban Pesach (Paschal Offering) at their Seder in addition to matza and maror (bitter herbs), Hillel would make a "sandwich" and eat all three together. He interpreted the Torah command to eat the Korban Pesach "with matzot and merorim" (Bamidbar 9:11) as a requirement to eat them all together This led to the conclusion that the taste of one of these foods did not neutralize the taste of the other and that he fulfilled all the mitzvot involved.
Although we have not yet merited to eat the flesh of the Korban Pesach at our Seder we do recall what Hillel did in his time by eating a matzah-maror sandwich after we have obviously fulfilled the mitzvot of matza and maror by eating them separately.