Negaim, Chapter 14, Mishnah 10. Our chapter has followed the metzora through the whole course of his purification, and we have reached the eighth day in the Beis Hamikdash. His asham has been slaughtered, two kohanim have received its blood, one into a kli shareis and one into his hand, and now the blood in the kohen's hand must be placed upon three specific spots on the metzora's body. This mishnah teaches how that was accomplished, and what happens when the necessary limbs are not there.
Where these halachos are codified
One orienting note before we learn the mishnah. The Rambam presents the laws of this stage of the metzora's purification not among Hilchos Tumas Tzara'as but in Hilchos Mechusarei Kaparah, which belong to the order of korbanos. A mechusar kaparah is someone who has already gone to the mikveh yet still owes a korban before kodashim become permitted to him, and the metzora belongs to this group along with the zav, the zavah and the yoledes. There the Rambam traces the sequence: after the metzora has spent his seven days in Yerushalayim, undergone his second shaving and immersed, he arrives on the eighth day and is positioned at the doorway of Sha'ar Nikanor with his face toward the west. That was the fixed station of every mechusar kaparah undergoing purification, and it was also where the sotah was made to drink her water.
Reaching in without entering
"Hichnis rosho," he puts his head through the opening. Since he is still a mechusar kaparah, walking into the azarah is closed to him. The mishnah, though, relies on the rule of "bi'ah b'miktzas": inserting only part of oneself does not carry the status of coming in, and therefore his head may cross the line.
The Rav lays out the two opposing pressures that forced this arrangement. One who lacks his kapparah may not set foot in the Ezras Yisrael. Yet "v'dam ha'asham hayah nifsal bayotzei": the blood of the asham, the very substance through which he becomes tahor, is disqualified by yotzei once it leaves the azarah, and even the Ezras Nashim has the status of outside in this regard. The only workable spot was Sha'ar Nikanor itself, the gateway that divides the Ezras Yisrael from the Ezras Nashim. He extends his head inward until the matanos are given on the tnuch of his ear, and likewise his hand and his foot until the blood is placed on thumb and toe. Throughout, it is self understood that we are speaking of the right side.
The meaning of "tnuch"
The Rav explains "tnuch" as the "geder emtza'i shel ozen": neither the upper rim nor the fleshy lobe underneath, but the ridge of cartilage that runs between them.
The Tosfos Yom Tov enlarges on this. He points out that Rashi, commenting on Parshas Metzora, states openly that he has no tradition as to what the word tnuch means. The Tosfos Yom Tov then cites Toras Kohanim in the version quoted by the Rosh. The midrash hears in the word the syllable "toch": "v'nasan al toch," shall we say the blood goes inside the ear? Against that the derashah answers "al noch." And if the reading is "noch," shall we say it goes on the high part of the ear? Against that comes "toch." "Ha keitzad?" How, then? "Zeh geder emtza'i," the ridge in the middle. No word "noch" is familiar to us, but the implication is that "tnuch" is a compound of "toch" and "noch," the latter apparently pointing to the outer portion. The Tosfos Yom Tov works at length to clarify this difficult ma'amar Chazal; in any case, this is the source behind the Rav's definition.
Three insertions or one
Follow the mishnah's order. First his head goes in, and the kohen gives "al tnuch ozno." Then his hand, and the kohen gives "al bohen yado." Then his foot, and the kohen gives "al bohen raglo."
Against this a dissenting view is recorded: "Shloshtan hayah machnis k'echad," teaches Rabbi Yehudah, all three were put through at one time. Evidently there were separate apertures available, so that ear, hand and foot could be presented at a single moment. The Rav notes that we do not pasken this way.
A metzora missing the limbs
The remainder of the mishnah records a dispute among three tannaim. What of a man who has "ein lo bohen yad," no thumb, or no "bohen regel," no big toe, or no "ozen y'manis," no right ear? According to the Tanna Kamma, "ein lo taharah l'olamim": purification will never be available to him. The Torah specified the ridge of the ear, the thumb of the right hand and the toe of the right foot, and where those matanos are impossible, the process can never be brought to completion. The practical loss is kodashim. Terumah and maaser remain permitted to him, and a kohen in this situation still eats terumah; what is closed to him forever is eating kodashim, bringing korbanos and entering the Beis Hamikdash.
"Nosein hu al m'komam," says Rabbi Eliezer: the blood is applied to the places where those limbs once were, since the pasuk is not to be pressed for literal exactness but is designating the areas that must receive the blood. The Rav writes that we do not follow Rabbi Eliezer; the halachah is as the first Tanna taught, and such a man remains without a path to taharah.
Rabbi Shimon offers a third position: if the kohen put the blood "al shel smol," on the left ear, the left thumb and the left toe, then "yatza," it is acceptable bedieved. Here too the Rav paskens otherwise. The matanos are required on the right.
At what point were they lost?
Many of the meforshim make a crucial distinction turning on when the limbs disappeared. Had the man lost them well beforehand, years, weeks or even a few days earlier, nothing is blocked, and taharah is still attainable. The absence is me'akeiv only when the loss occurred after his purification was already under way, in the course of these seven or eight days; then, since we hold like the Tanna Kamma, no purification will ever be possible for him.
The Tiferes Yisrael observes that this makes the Rambam difficult, "shelo chileik hacha bein nikde'u kodem shenizkak l'mitzvah": no distinction is drawn there between limbs lost before the man became obligated in this mitzvah and limbs lost once he was. He leaves it standing as a kashya, and its answer belongs to another discussion.
So the mishnah ends, and with it the metzora who has finished his taharah is restored in full: he re-enters the Beis Hamikdash, resumes his korbanos, and returns to the kodashim that his nega had barred him from.