Negaim, Chapter 13, Mishnah 10. This chapter deals with the tumah of a bayis menuga, a house in which the nega of tzora'as has appeared. Our mishnah is a fundamental one, and it turns on a distinction that is easy to miss: the difference between clothing a person is carrying into such a house and clothing he is actually wearing.
"Mi shenichnas labayis hamenuga vecheilav al kesefo": someone who walks into an afflicted house with his clothing folded over his shoulder instead of worn on his body, "vesandalav vetaba'osav beyadav", gripping his footwear and his jewelry rather than having them on his feet and fingers, "hu vahen temei'im miyad": the man and the objects alike are rendered tomei at that very moment. Vessels that cross the threshold of such a house acquire tumah in their own capacity as keilim.
"Hayah lavush becheilav, vesandalav beraglav, vetaba'osav beyadav": but if he was dressed in his garments, with his sandals on his feet and his rings on his fingers, "hu tamei miyad": he himself is tomei the moment he enters, "vehen tehorin ad sheyish'heh kedei achilas pras": but they remain tohor until he stays inside long enough to eat a pras, half a loaf. The Mishnah then defines the loaf precisely: "pas chittin velo pas se'orim", wheat bread and not barley bread, "meiseiv ve'ochlan belifsan", while reclining and eating the bread together with a condiment.
The Rambam: The Pesukim Are Giving Us a Clock
The Rambam builds the mishnah out of the pesukim in Vayikra, chapter 14. First the Torah says "vehaba el habayis kol yemei hisgir oso yitma": one who enters the house during all the days of its quarantine becomes tomei. This is the period of hesger, after which, if the house does not turn out clean, it must be demolished. From here, says the Rambam, the Torah has informed us that whatever is inside a bayis menuga becomes tomei.
Then the Torah continues, "vehashocheiv babayis yechabeis es begadav", one who lies down in the house must launder his garments, which by its plain sense would suggest that a person's clothing is affected only if he lay down inside. But the pasuk goes on, "veha'ocheil babayis yechabeis es begadav", one who eats in the house must launder his garments. And there is no reason to distinguish between eating and lying down, for it is not the act of eating that brings tumah upon the clothing.
Rather, the intent of the Torah is what Chazal state in the Sifra: litein shiur, to supply a measure. The Torah pictures a man eating while reclining in order to tell us how long a person must remain in an afflicted house before the garments he is wearing require kibus, laundering. The measure is the stretch of time in which a man could recline (as people in those days reclined on couches to eat) and eat half a loaf of wheat bread together with one of the condiments eaten with bread. Once he has lingered that long, the garments upon him are tomei. Whether he actually ate or did not eat, whether he was lying, standing or in any other position, is irrelevant. The whole point is that he remained there for that span of time.
Why does the Mishnah specify wheat bread with a condiment? Because that combination is eaten in the shortest time. One might have assumed the opposite, that adding a spread would slow a person down, but the Rambam explains that good bread eaten with a condiment goes down quickly and does not require lengthy chewing.
How much is a pras? Half a loaf, and the Rambam quantifies it as three average eggs, hens' eggs, as he explains in the eighth perek of Eiruvin. Here we meet the well known machlokes that runs through the entire Torah wherever this measure appears. The Rambam holds that a whole loaf is six eggs, so a pras is three; Rashi holds that a loaf is eight eggs, so a pras is four. In our case Rashi's view is the more lenient one, since eating four eggs' worth takes longer than three, and the worn garments therefore stay tohor for a longer stretch.
The Rav: Carried as a Burden
The Rav: Carried as a Burden
The Rav sharpens the details. "Cheilav al kesefo" describes garments folded up and lying across his shoulder derech masoi, the way a person transports a load. "Taba'osav beyadav" means the rings are clutched in his fist, not positioned as a ring is ordinarily worn. In such a case tumah takes hold of the man and the objects alike from the moment of entry, since regarding keilim too the Torah writes "vehaba el habayis yitma", and these items came inside as independent objects.
When he is wearing them, however, they are not tomei on their own account as keilim; they can become tomei only as his clothing, because of his own tumah. And for that, he must remain in the house for the shiur of kedei achilas pras, as derived from the pesukim "veha'ocheil babayis yechabeis es begadav" and "vehashocheiv babayis yechabeis es begadav".
The Rav quotes the braisa: ein li ela ocheil veshocheiv, from the pesukim I would know only about one who eats and one who lies down; lo ocheil velo shocheiv minayin, from where do I learn about one who neither eats nor lies down? Talmud lomar "yechabeis begadav", ribah, the extra phrase comes to include every case. If so, why does the Torah mention eating and lying at all? Litein shiur lavo el habayis, to give a measure to one who comes into the house: his garments do not require laundering until he remains there long enough to eat a meal in a reclining position, klomar shehu meiseiv, that is, in the leisurely posture of a reclining diner.
And how much is that shiur achilah? Kedei achilas pras, which is the half loaf spoken of in Eiruvin in connection with eiruv chatzeiros. The Rav records the machlokes there as well: according to Rashi it is four eggs, according to the Rambam three.
Finally, the Rav explains the closing words, "meiseiv ve'ochlan belifsan", that the measure of time is the shorter one, less than when the bread is eaten plain, because the good taste of the condiment sharpens a person's appetite and he swallows the bread down faster.
The mishnah's message, then, is precise. An item brought inside a bayis menuga in its own capacity is tomei from the very first instant. Garments worn on a person's body have no independent standing there; their fate is bound to his, and only once he has settled in for the span measured by a reclining diner finishing off a half loaf of wheat bread together with a relish.