Negaim, Chapter 9, Mishnah 3. Three mishnayos make up this chapter, and all of them treat the nega that appears upon a wound: shechin and michva. A shechin is a sore or bruise brought on by anything having nothing to do with flame, including heat that is not fire based, as with the warm springs of Teveria, whose warmth rises from beneath the ground; a michva is damage caused by flame itself or by something that flame has heated. In these negaim the confinement never runs longer than a single week: when that week ends, the Kohen either sends the man off tahor or, if something has altered, declares him a muchlat.
Two of the three signs of tumah operate in a shechin or michva. If a baheres, a white spot, appears in the place of the wound, it can become tamei through se'ar lavan, two hairs that turned white, and through pisyon, the spreading of the baheres. Michya, a patch of living flesh inside the baheres, has no application here, since michya means healthy skin and we are dealing with a wound.
One more piece of background is needed for our mishnah. A wound that is still raw and running, with moisture in it, whether lymph or pus, is tahor even if a baheres appears on it. The moment of vulnerability is at the start of the healing, when a thin membrane forms over the sore, no thicker than the peel of a clove of garlic. That stage is called "tzareves hashechin," the scab of the boil spoken of in the Torah, and the same applies to a burn. If, on the other hand, the wound healed completely, even though a scar remains in its place, the area reverts to being judged as ordinary skin, with all three signs of tumah once again in play.
The Question Put to Rabbi Eliezer
"Sha'alu es Rabbi Eliezer," a question was brought before Rabbi Eliezer, that is Rabbi Eliezer ben Hurkenus: "Mi shehayah bo baheres kasela," a man had upon him a baheres as wide as a sela, a substantial coin, far larger than a gris, and it lay on his palm, "umekom tzareves hashechin," while the skin beneath it was tzareves hashechin, a boil that had already formed that garlic-peel covering. How is such a case to be ruled?
"Omar lahem, yaskir." Rabbi Eliezer answered that the Kohen places him under hesger.
"Amru lo, lamah?" They challenged him: what purpose could the hesger possibly serve? Go through the signs one by one. Se'ar lavan is out of the question, "lega'del se'ar lavan einah re'uyah," the palm of the hand is not a place where hair grows, so there can never be two white hairs there. (As a curiosity, Yaffa Eliach's Hasidic Tales of the Holocaust records a striking story of a man whose life was saved because he did have hair growing on his palm, but that was the result of a transplant. In the natural order of things, the palm does not grow hair.) Pisyon is equally impossible: a baheres that began in a shechin or michva does not spread into ordinary skin, and since the baheres is as large as, or larger than, the wound beneath it, there is simply nowhere for it to spread. And michya cannot apply, since a nega that originates on a wound is removed from the parshah of michya altogether, so that even if part of the baheres extends beyond the wound and contains living skin, it does not render him tamei. If none of the three signs can ever appear, why should the Kohen bother to close him up for a week?
Rabbi Eliezer's Answer
Rabbi Eliezer replied: "Shema tichnos vetifseh." It is possible that the baheres will first draw inward and only later expand. The Rav lays out how this would unfold: once the week has run its course, the spot may have receded until it measures no more than a gris. Contraction is not treated as a turn for the worse, and with neither white hairs nor spreading in evidence, the Kohen who inspects him then sends him away clear, "yaftir oso." The Rav's choice of a gris is deliberate: whatever remains must be at least that size, since anything below a gris is not subject to the law of pisyon in the first place.
"Ule'achar haptur tagzor vetifseh betoch hashechin." Now, after he has already been released as tahor, that gris-sized baheres spreads a little within the boil itself. The wound was the size of a sela, so there is ample room inside it for the baheres to expand, and pisyon within a shechin or michva is a full sign of tumah. Since the man had already been dismissed as clean, this is a pisyon after ptur, which renders him tamei. That is the practical difference, the nafka mina, that justifies the hesger from the outset.
"I Did Not Hear"
"Amru lo, vahalo mekomah kegris?" They pressed further: and what if the wound itself is only the size of a gris, exactly the size of the baheres sitting on it, so that there is no room even inside the shechin for the spot to spread? "Omar lahem, lo shamati," he replied, I have not heard.
The Tosfos Yom Tov observes that this answer is entirely in character. Rabbi Eliezer said "lo shamati," I have not heard, and not "lo yadati," I do not know. As the Maharam of Rottenburg explains in his writing, this master never said a thing that he had not heard from his own teachers, as the Gemara records in Sukkah 28a.
Rabbi Yehuda ben Beseira Supplies the Answer
At that point Rabbi Yehuda ben Beseira spoke up and offered to explain the case: "Alameid bo." Rabbi Eliezer granted him permission, but with a condition: "Im lekayem divrei chachamim, hein" - if what you are about to say will confirm the ruling of the Sages, then speak.
His explanation ran: "Shema yivoleid lo," perhaps there will arise for him, "shechin acher," an additional boil, "chutzah lo, veyifseh letocho." Even where the sore measures a mere gris and the white spot blankets every bit of it, the week of confinement is not pointless, for a second boil may erupt right beside the first, and the baheres may then extend itself into that new area. The new growth has to be a boil and not a burn, since a shechin and a michva neither combine with one another nor spread from one into the other; a boil pairs only with a boil, a burn only with a burn. Once a newly formed sore borders the old one, there is room for a pisyon once more, and the Kohen's hesger proves to have been well founded.
Rabbi Eliezer's response was warm: "Chacham gadol atah," you are a great sage, "shekiyamta divrei chachamim," for you have vindicated what the Chachamim taught. On that note the mishnah draws to a close, and with it the ninth chapter of Negaim.