Negaim, Chapter 7, Mishnah 5. Our chapter opened with the words "Eilu baharos tehoros", listing baharos that can never become tamei, and it went on to deal with a baheres whose shade changed, where the halachah follows Rebbi Akiva that the nega is viewed afresh and the person is placed in hesger. The chapter now closes with a person who takes matters into his own hands: instead of waiting for the kohen's ruling, he removes the evidence.
The prohibition
The Mishnah opens: "Hatolesh simanei tumah vehakoveh es hamichyah". One who plucks out the simanei tumah, for example the white hairs within the nega, or who burns the michyah, since burnt flesh is no longer healthy flesh and the michyah is thereby destroyed, "over belo sa'aseh", he transgresses a negative commandment of the Torah.
The Rav identifies the lav: "hishamer benega hatzara'as", the Torah's warning to be careful with the nega of tzaraas. And he adds the well known principle of the Gemara: wherever the Torah says hishamer (be careful), pen (lest), or al (do not), eino ela lo sa'aseh, the expression is nothing less than a negative commandment. Hence one who removes his own simanei tumah has violated an issur.
And what of his taharah?
Now comes the question of status: "uletaharah", what is the halachah as far as purity is concerned? Everything depends on when he acted. Did he do it before any examination took place, "ad shelo ba", before he came, "etzel hakohen", to the kohen? Then the ruling is "tahor". The sin he committed is real, but with the signs gone there is nothing left in front of the kohen upon which a hachlatah could be pronounced. And if the declaration had already been made, "le'achar hechlaito, tamei": once he was pronounced a muchlat, and only then did he tear out the hairs or scorch the michyah, his tumah remains exactly where it was. Getting rid of the sign with his own hands accomplishes nothing for him; had it faded away by itself, that would have been another matter.
Rebbi Akiva Eiger
There is an important comment of Rebbi Akiva Eiger here. On the words "le'achar hechlaito tamei" he writes that this tumah is simply a knas, a penalty of the Rabbanan. Min haTorah, a muchlat who plucked out his white hairs or burned his michyah is not held back: he is permitted the tiglachas together with the birds, which open the process of his purification, he may count his days of taharah, and he becomes tahor min haTorah. Where the penalty bites is in the kaparah. He cannot bring the korbanos that complete his purification, because as long as he is tamei miderabbanan he may not insert his hands and his thumbs and toes through the opening of Sha'ar Nikanor, as Rebbi Akiva Eiger cites from Tosfos in Bechoros 34b.
Rebbi Akiva's question on the road
The Mishnah now records a tradition. "Amar Rebbi Akiva: sho'alti es Rabban Gamliel ve'es Rebbi Yehoshua holchin leGadvad": Rebbi Akiva relates that while they were traveling to Gadvad, he asked Rabban Gamliel and Rebbi Yehoshua a question. The two rulings he had received addressed the two extremes: one who plucks before the kohen has seen him at all, and one who plucks after hachlatah. But what about the middle stage? "Hatolesh simanei tumah betoch hesgero, mah hu?" During the week of hesger a siman tumah suddenly appears and the man pulls out the hair or burns the michyah. What is his status?
Their response was "amru lo: lo shamanu": no tradition concerning that intermediate case had reached them. "Aval shamanu", what they had received dealt only with the two extremes: one who acted before ever presenting himself to a kohen remains tahor, and "ule'achar hechlaito tamei", once hachlatah has been pronounced upon him he is tamei.
The proofs
"Hischalti meivi lahem rayos", says Rebbi Akiva: he proceeded to argue the point with them. Our Mishnah leaves the arguments unstated, and the Rav therefore sends us to the Tosefta on Negaim, the Tannaitic collection that runs alongside the Mishnah, where they are set down. The argument went like this. What is the basis for declaring tahor the man who plucked before the kohen arrived? Nothing other than the fact that no siman of tumah was ever observed upon him by a kohen. That very consideration applies word for word to the man who plucks during his week of hesger, for in his case too no kohen ever laid eyes on a siman of tumah, and by rights he should be tahor as well.
And that is how the Mishnah rules. Both cases are placed in a single category: "echad omeid bifnei hakohen", one who does this while standing before the kohen prior to any decision, "ve'echad betoch hesgero", and one who does it during his period of confinement, both are "tahor". As long as no kohen ever observed a siman of tumah upon him, he retains his purity, "ad sheyitmeinu hakohen", up until the point that a kohen actually pronounces him tamei.
When can the muchlat ever become tahor?
The Mishnah closes with the difficult case: a man who was already declared muchlat and then destroyed his simanei tumah, so that his tumah remains fixed upon him. "Me'eimasai taharaso?" When can such a person ever emerge tahor?
"Rebbi Eliezer omer: sheyavo lo nega acher veyitaher mimenu": Rebbi Eliezer says that a second nega must come upon him, and he must be purified from that one. The Rav explains the logic: everything here is from Heaven. Since he was healed of the second nega, the matter is revealed that Hakadosh Baruch Hu has now had mercy upon him, and had the first nega still been standing upon him, he would have been healed of it as well. His purification from the second therefore carries the first along with it.
"Vachachamim omrim: ad shetifrach bekulo": the Chachamim are more stringent. It is not enough that he be healed of the second nega in any manner; the second nega must resolve itself through pisyon, spreading until his entire body is covered with the baheres, the prichah that renders a person tahor. Their reasoning follows the same track: if that is how the later nega ends, then had the first one still been present it too would have been rendered tahor in that way, and so he is tahor now. In other words, the Chachamim demand that the avenue of taharah be the full covering of the body with tzaraas, a far more demanding matter than the mere disappearance of the simanei tumah from the second nega, which suffices for Rebbi Eliezer.
The Chachamim mention a second route as well: "o ad shetisma'et bahereto", or the original baheres, the very one from which he tore away the simanei tumah, may shrink until it is "mikagris", smaller than a gris, which is the minimum shiur for a nega altogether. On that note our chapter comes to a close.