Keilim, Chapter 8, Mishnah 10. Our chapter has been occupied with a recurring theme: an item that sits inside something else, while that something else is suspended in the airspace of an earthenware oven. Until now the discussion revolved around keilim placed within the oven's airspace. This mishnah takes the identical question and applies it to a person: what happens when the "container" holding the food is a human mouth?
Tame food in the mouth, tahor oven
Our mishnah opens with the words "maga tamei met shehayu ochalin umashkin letoch piv": a man who took on tumah by coming into contact with someone who had himself been rendered tame through a human corpse, and inside whose mouth there happen to be items of food along with something to drink.
Follow the descending count step by step, since every stage loses one degree. A corpse holds the rank of avi avot hatumah. Whoever comes into contact with it acquires the rank of av hatumah. The man of our case touched that individual, so he now stands as a rishon. And whatever was edible or drinkable resting in his mouth at that moment takes the next rank down, sheni la'tumah.
The mishnah goes on: "vehichnis rosho la'avir tanur tahor," he placed his head inside the hollow of an earthenware oven that was tahor. The verdict is "timuhu": those sheni liquids sitting in his mouth make the oven tame.
How can that be? By Torah law, the only source capable of transmitting tumah to a keli is an av hatumah, or something more severe still. Anything ranked as a rishon, or lower down, lacks that power. Since the man in question holds no more than the rank of rishon, he could never on his own make the oven tame. The Chachamim, however, legislated a special stringency for liquids: tame liquids do pass tumah on to keilim, and this holds not only for liquids that are a rishon but even for those that are merely a sheni. What drove the decree was the worry that people would grow careless with the secretions of a zav and a zavah, which carry the rank of av hatumah by Torah law and make keilim tame. So that nobody confuse the two categories, the Sages extended the severity to tame liquids across the board. It follows that the sheni liquids inside this man's mouth are genuinely able to make the oven tame.
One might have supposed that liquids held within a closed mouth are screened off, just as earlier mishnayot in this chapter preserved the taharah of items lodged in the inner cavity of a second keli standing in the oven's hollow. That leniency, though, flows from the way keilim are constructed, and it has no application to a human mouth. A mouth does not qualify as a keli, and halachah does not view it as a sheltered compartment. Whatever it holds is judged as though it were sitting in the oven itself.
Tahor food in the mouth, tame oven
The reverse scenario comes next. "Vetahor," and so too a man who is tahor, "shehayu ochalin umashkin letoch piv," with tahor edibles and drink resting inside his mouth, "vehichnis rosho la'avir tanur tamei," who then places his head inside the hollow of an oven that has become tame. In this direction, what he holds in his mouth turns tame, since it now sits within the inner space of a tame oven.
Both directions rest on a single idea. A mouth forms no barrier between what it holds and the oven. Lacking the status of a keli, it can shield nothing, so its contents are judged as if they were resting in the cavity of the tame oven, and that is precisely why they turn tame.
Saliva: is it a liquid?
A fresh subject now opens up: how does halachah classify the spittle inside a person's mouth? The case is this. "Haya ochel develah," a man was eating a pressed fig cake, "beyadayim meso'avot," with hands that had not been washed, "hichnis yado letoch piv litol et hatzror," and he reached inside his own mouth to extract a small stone that had gotten mixed in among the figs.
"Rebbi Meir metamei." According to Rebbi Meir, what he holds in his mouth has become tame. Here is the logic. Spittle carries the halachic standing of water: it counts as a mashkeh, and like water it functions as a machshir, readying food to be capable of receiving tumah. Hands that have not been washed are automatically assigned the rank of sheni, which is exactly the rank that netilat yadayim removes. Counting strictly, a sheni hand would leave the spittle a shelishi, a level with no bite for ordinary food, relevant only to terumah or kodesh. But the Chachamim ruled that any liquid which takes on tumah becomes a rishon. So the sheni of his hand raised the spittle to rishon, the spittle in turn brought the figs down to sheni, and food of sheni rank is truly tame even in the realm of chulin.
"VeRebbi Yehuda metaher." Rebbi Yehuda holds that the figs remain tahor. In his view, saliva is not treated as a liquid for the purposes of the laws of tumah as long as it is still inside the mouth. It is considered part of the person's body rather than an independent liquid, and it can become tame only once it has left his mouth.
The middle position of Rebbi Yose
Rebbi Yose positions himself between the other two: "im hafach, tamei." Should he have already moved the figs from one side of his mouth to the other before his fingers arrived, they are tame. The reason is that the spittle clinging to them has been shifted out of the spot where it lay, and that displacement grants it independent standing as a liquid, mouth or no mouth. Everything was thereby made fit to receive tumah, and everything did receive it.
"Im lo hafach tahor." If he had not yet shifted the figs when his hand entered, they remain tahor. Nothing was displaced, the saliva is still simply the moisture of the mouth, and it is therefore not reckoned as a liquid at all.
The coin in the mouth
There is one case in which Rebbi Yose would rule that the saliva becomes tame even without any shifting of the figs. "Haya pundyon letoch piv," he had a pundyon, a coin, in his mouth. Certain metals react in the mouth and cause a person to produce more saliva, and people would put a coin in their mouth for exactly that purpose.
"Rebbi Yose omer im litzma'o tamei." Should he have taken the coin between his lips as a remedy for thirst, knowingly drawing out spittle because he was aware of the coin's effect, tumah reaches the figs even where no turning over has taken place. Spittle that a person produces by design counts as a liquid from the outset. It is no longer the body's natural moisture but something generated on purpose, and so Rebbi Yose grants it full standing as a liquid with no displacement required at all. Being a liquid, it takes on tumah from his unwashed hands, and it hands that tumah along to the figs it surrounds.
So this mishnah teaches us two lessons at once. A person's mouth grants no protection from an oven's airspace in either direction, because a mouth is not a keli. And the moisture within that mouth stands or falls on a single question that the Tannaim debate: at what point does saliva stop being part of a person's body and start being a liquid?