We are continuing in chapter three of tractate Kerisos, which deals with the possibility that a person might become liable for several offerings - primarily several chatas offerings - for a single act. In the previous Mishnah we discussed a case of a mixture that contained four different prohibitions - nosar, blood, chelev, and the like - and we learned that even if the person ate everything in a single lapse of awareness, since he transgressed different commandments, he is liable for a separate chatas offering for each and every one of them that carries a penalty of kares.
Our Mishnah goes even further: there can be a situation where a single kezayis of meat is forbidden in several ways, and the one who eats it transgresses all the prohibitions at once and becomes liable to bring an offering for each and every one of them.
The rule: A prohibition does not take effect upon an existing prohibition:
Before we approach the Mishnah itself we must introduce an important rule: 'A prohibition does not take effect upon an existing prohibition' - a new prohibition does not take effect on something that has already been forbidden. For example, horse meat is forbidden to eat because a horse is not a kosher species. Once the horse dies it becomes a neveilah, and the laws of neveilah tumah take effect upon it, and there is also a separate Torah prohibition against eating neveilah meat. Nevertheless, someone who eats a kezayis of meat from a horse that was not slaughtered is only liable for one punishment and not two, since even during the horse's lifetime its meat was forbidden, and the new prohibition does not take effect upon the existing prohibition.
The three exceptions:
An added prohibition (issur mosif): When the new situation adds to the existing prohibition and expands it. This can occur in two ways: One - that the prohibition itself becomes more stringent, such as if until now the object was only forbidden to eat and from now on it is also forbidden for benefit; and the second - that the object becomes forbidden to additional people. For example, someone who consecrates a horse: from now on its meat is not only forbidden to eat because it is horse meat, but it is also forbidden due to being consecrated property (hekdesh), and one who eats it is liable for two separate things.
An encompassing prohibition (issur kolel): A broader prohibition. If the scope of the prohibition expands and encompasses within it a more general prohibition and additional people - the circle of prohibition grows. While an added prohibition adds intensity and stringency to the forbidden object itself, the concept of an encompassing prohibition is that additional people are restricted by that prohibition. It too takes effect, and a second layer of prohibition is added, such that the person becomes liable for two things.
Simultaneous prohibitions (issur b'vas achas): When two prohibitions take effect at the exact same time. For instance, Shabbos that falls on Yom Kippur - work is forbidden on Shabbos and forbidden on Yom Kippur, and the two prohibitions came at once; or a woman who is both a person's daughter and his sister from the moment of her birth, such that she is forbidden to him from two sides and he is liable for her due to being a daughter and due to being a sister.
It emerges that the rule 'A prohibition does not take effect upon an existing prohibition' remains in place, but it has three exceptions - an added prohibition, an encompassing prohibition, and simultaneous prohibitions - and all of them will find expression in our Mishnah.
The case in the Mishnah: Five prohibitions on a single kezayis:
The Mishnah presents a possibility that a single kezayis of meat becomes forbidden in several ways, one after the other, until the one who eats it becomes liable for four chatas offerings and an asham offering. This is how the events unfold:
Chelev: A cow contains chelev - forbidden fats - from the moment it is born. Eating chelev is forbidden with the penalty of kares, and one who eats it inadvertently brings a chatas. This is the first chatas.
Hekdesh (an added prohibition): A person consecrated the cow as an olah offering. From now on, its chelev is not only forbidden to eat, but it is also forbidden for benefit - one may not use it to light a candle or for other needs. This is an addition of restrictions on the chelev, and therefore the new prohibition takes effect upon it. The one who eats it is therefore liable for two things: for the chelev in and of itself, and for deriving benefit from hekdesh, which is me'ilah. For the first - a chatas, and for the second - an asham offering for me'ilah, as well as returning the principal value and adding a fifth.
Tumah (an encompassing prohibition): The person became tamei, and from now on a new world of restrictions goes into effect. While tahor he could not eat chelev, but he could eat kosher sacrificial meat of that very same animal (if it were a shelamim offering). Once he became tamei - all sacrificial meats became forbidden to him, including the chelev of that offering. The circle of prohibition around him has expanded, and this is an encompassing prohibition. This is the second chatas.
Nosar (an added prohibition): That chelev was not offered but remained beyond its designated time, becoming nosar, and its prohibition carries kares. This is an added prohibition, since from now on the chelev is forbidden not only to all people but even to the Altar, for we do not offer nosar. Not only may one not eat from it, as was the case beforehand, but one may not even offer it anymore. This is the third chatas.
Yom Kippur (an encompassing prohibition): Yom Kippur arrived, on which all foods in the world are forbidden, and among them this piece of consecrated, leftover chelev. This is an encompassing prohibition, for Yom Kippur forbids all foods entirely. This is the fourth chatas.
It emerges that five prohibitions took effect one on top of the other, despite the rule that 'a prohibition does not take effect upon an existing prohibition,' because each of these stages is an added or encompassing prohibition. One who eats this kezayis on Yom Kippur while tamei, from an animal that was consecrated, and after the meat became nosar - is liable for four chatas offerings and one asham offering.
The language of the Mishnah:
"Yeish ochel achilah achas vechayav aleha arba chataos ve'asham echad" - A person could eat a single k'zayis and be liable for it with four sin offerings and one guilt offering. In what case are we speaking? "Tamei she'achal chelev, vehu nosar, min hamukdashin, u'veYom Hakippurim" - Here we have all five layers that were explained.
Rabbi Meir adds: "Im haysah Shabbos vehotzi'o befiv - chayav" - if it was Shabbos and he carried it out in his mouth, he is liable. That is, had the incident occurred on Shabbos, and the person ate the piece while going out from a private domain to a public domain, he would also be liable for desecrating Shabbos - and if he did so inadvertently, he would owe an additional sin offering for a prohibition punishable by kares. "Amru lo: Eino min hasheim" - The Sages answered him that this is not the subject of the Mishnah: we are dealing with the prohibitions of eating that piece, and carrying is a different matter and does not apply here.
Why did Rabbi Meir specifically mention Shabbos?
This is seemingly puzzling, since carrying is also prohibited on Yom Kippur: it too is a "Shabbos Shabbason", and melachah performed on it is punishable by kares. The Gemara explains that Rabbi Meir means to say that if the incident occurred on Shabbos, he would be liable not for one additional offering but for two additional offerings, thus making him liable for six sin offerings and a guilt offering. This is a side point.
Rabbeinu Tam's explanation:
The main point is deeper. This is not a game where one tries to combine the most extreme scenario of transgressions committed simultaneously - since one could have added that at the same time he cohabited with his sister and the like - and even Rabbi Meir knows this is not the point.
Rabbeinu Tam explains: While carrying on Shabbos is indeed punishable by kares, and one who does so inadvertently is liable for a sin offering, the laws of Shabbos are conditional on "meleches machsheves" - that the melachah is performed in its normal, calculated, and efficient manner. One who takes a pen and carries it in his mouth on Shabbos is not liable by Torah law, and it is only a rabbinic prohibition, because there is a deviation from the normal manner of carrying, as people do not normally carry pens in their mouths. However, with food, the normal way to carry food when a person is walking and eating it is in his mouth, while chewing.
Therefore, one who carries food in his mouth on Shabbos while eating it - this is its normal manner of carrying, and he is therefore liable for an additional sin offering. And his main point is: this liability comes to him only because of the eating. Indeed, our Mishnah deals with liabilities that combine in a single act of eating, and had he not been eating, he would not be liable for carrying the piece of food in his mouth. This is his approach.
The Sages, on the other hand, do not disagree with this in principle, and they admit that one who eats this piece of chelev on Shabbos or Yom Kippur in this manner is liable for six sin offerings and a guilt offering. Rather, in their opinion, this is not the subject of the Mishnah: the Mishnah deals with the piece of food and the prohibitions that took effect on it, not with the act of eating itself. Rabbeinu Tam, however, maintains that we are dealing with eating, and therefore this liability also joins the list.
In summary: In this lesson we learned the rule of "ein issur chal al issur" and its three exceptions - issur mosif, issur kolel, and issur bevas achas. We saw how five prohibitions combine on a single k'zayis of chelev - chelev, hekdesh, tumah, nosar, and Yom Kippur - until the one who eats it is liable for four sin offerings and one guilt offering. We also discussed Rabbi Meir's statement regarding the addition of the liability for carrying on Shabbos and the Sages' response "eino min hasheim", as well as Rabbeinu Tam's explanation, that carrying food in the mouth while eating it is a normal manner of carrying, and its liability comes about due to the eating itself.