Negaim, Chapter 8, Mishnah 9. This chapter is devoted to pricha, the case in which a baheres spreads out and covers the entire body of the person. The governing principle of the perek is that a spread which emerges from a state of tumah brings taharah, while a spread which emerges from a state of taharah brings tumah. Our mishnah continues directly from the case discussed just before it, and then turns to a second subject entirely: what separates a metzora who is under quarantine from one who has been definitively declared tamei.
A Spread That Comes All at Once
The case is this: the tzaraas had covered the man's whole body, and then the rashei evarim, the extremities, became exposed, so that healthy skin was visible on them. Now the tzaraas spreads again and covers the entire body, including those extremities, "ke'achas", all at one time. Some of the mefarshim understand this word to be describing the speed of the spread: this was not a gradual creeping outward, but a sudden eruption, a genuine blight that overtook the whole body at once.
The outcome is decided by the chapter's governing principle. Where the eruption breaks out over a man who was already standing in tumah, its effect is to purify him; where it breaks out over a man who was standing in taharah, its effect is to defile him. Hence the mishnah's two clauses: "mitoch hataharah", he becomes tamei, and "umitoch hatumah", he becomes tahor.
The Chiddush According to the Tiferes Yisroel
But if the perek already opened with that very rule, what has been gained here? The Tiferes Yisroel raises the question and resolves it. At the head of the chapter, he explains, the distinction was presented only with regard to an ordinary baheres of modest size that later spread over the man. Our mishnah extends the identical halachah to a baheres that is already vast, one that had covered him from head to foot with only the extremities left clear: here too, a fresh outbreak emerging from tumah purifies, and one emerging from taharah defiles.
Musgar and Muchlat: Four Obligations
At this point the mishnah takes up a fresh subject: "Hatahor mitoch hesger", one who reaches taharah at the end of a quarantine, is "patur min hapriah umin haprimah umin hatigalachas umin hatziporim", exempt from four obligations, while "mitoch hachlet chayav bekulan", one who reaches taharah after having been definitively declared tamei is bound by every one of them.
The commentators observe that the phrasing here is harder to follow than the parallel teaching in Megillah, chapter 1, mishnah 7, which sets the material out as a series of ein bein contrasts. That mishnah divides the matter into two periods. During the affliction itself, a metzora in quarantine and a metzora declared tamei differ in two respects only, periah and primah: the muchlat must leave his hair untrimmed and must go about in torn garments with his head covered in the manner of a mourner, while the man under quarantine is free of both. At the stage of purification, the one who emerges tahor from a quarantine and the one who emerges tahor after having been muchlat differ in two respects only, tigalachas and tziporim.
Tigalachas is the removal of every hair on him, shaved off with a razor. Tziporim refers to the pair of birds: the first is released and flies away, while the second is shechted and its blood mixed into the water that is then sprinkled on the metzora, upon his ear and upon his toe.
Our mishnah delivers the same halachah, only from the direction of exemption. The man whose taharah arrives at the close of a hesger was released from periah and primah while he sat shut away, and he is released from tigalachas and tziporim when the process concludes: no razor is passed over him, and no pair of birds is offered on his behalf. "Mitoch hachlet chayav bekulan": the one who had been pronounced muchlat carries all four duties, periah and primah for as long as the affliction rests on him, and tigalachas and tziporim at the time of his purification.
That shaving and those birds belong to the very moment he is pronounced tahor. A second tigalachas follows later, once the week he must count has run its course, and on the eighth day come his immersion and the offering of his korban, matters we will study in the closing perek of the maseches, perek yud daled.
Tumas Bi'ah: Both of Them Convey Tumah by Entering
The mishnah's final clause reads: "Vezeh vezeh mitam'in bebi'ah." On this point the quarantined metzora and the confirmed metzora stand on exactly the same footing, since each of them transmits tumah by entry. The Rav makes it concrete: the moment such a man steps into a tent or a dwelling, everything found within it contracts tumah.
Mareh Kohen: Four Distinctions Between Tumas Bi'ah and Tumas Ohel
The author of the Tiferes Yisroel was a formidable halachist. To Maseches Shabbos he prefaced a composition called Kelalei Shabbos, a masterly presentation of the laws of Shabbos, and to Negaim he prefaced an essay titled Mareh Kohen. In that essay he examines the tumas bi'ah of a metzora alongside the tumas ohel of a meis, and he isolates four practical differences between them.
- How much has to be present. A meis defiles whatever shares its tent, and even a fragment of the corpse is enough, provided it amounts to a kezayis. The metzora, by contrast, defiles through an act of coming in, which means rosho verubo is required, his head together with the larger part of his body. On the same logic, should he back his way in, that reversed movement, bi'ah achronis, is not reckoned as an entry at all.
- The effect of a barrier. With a meis, even a lofty wall inside the house fails to hold the tumah back when there is an opening measuring a tefach by a tefach; the tumah travels through and reaches whatever lies beyond. With a metzora, a standard mechitzah of the kind found all over the Torah, ten tefachim tall, does its work, and a tahor person who stands behind it stays tahor.
- Moving through versus remaining. Carry a meis beneath a tent and every tahor item under that tent is defiled. A metzora who is over, who merely passes beneath a covering (a canopy set upon poles, for example) without halting, transmits nothing by ohel. Walking into a house is a different matter altogether: that constitutes bi'ah, and it defiles even while he continues on his way.
- The grade of tumah produced. A meis defiles people and utensils alike and raises them to the level of an avi avos hatumah; every person and every vessel in the house becomes avi avos hatumah. The metzora who walks into a house produces something far lighter: whatever is inside becomes no more than a rishon letumah.
So the mishnah has given us two lessons: that the rule of pricha out of tumah and pricha out of taharah applies even to a baheres already covering the entire body, and that the practical gap between musgar and muchlat is narrow, consisting of periah and primah during the affliction and tigalachas and tziporim at the purification, while in the matter of conveying tumah by entering a house the two are entirely equal.