This is a fairly long-handled question, but it boils down to a desire to understand R' Shimon's qal vechomer in the Mishna, Negaim 10:2. Usually, for a qal vechomer to work, there needs to be a relationship of some description between its different components, and an indication that one half of the equation is more severe than the other. The following is the background to his qal vechomer and the qal vechomer itself:

In the Mishna, Negaim 10:2, R' Shimon produces a qal vechomer in order to make a point: that when it comes to tzara'at in the beard or on the head (נתק), thin, yellow hairs are an indicator of impurity only if the blemish predates it. His proof relies on the fact that in regular skin blemishes (בהרות), white hairs are only an indicator of impurity if they are preceded by the blemish. The technical term for this is הפוך: that the blemish "turned" the hair white.

In producing a qal vechomer, R' Shimon relies on a key difference between the baheret (the skin blemish) and the neteq (the blemish in the beard/head): when it comes to a skin blemish, while white hairs are a sign of impurity, there is no type of hair that can serve as a sign of purity - in other words, the presence of two white hairs is enough to render the skin blemish impure, regardless of how many black hairs there are. When it comes to a blemish on the beard or head, the presence of black or red hairs will purify the blemish, regardless of how many thin, yellow hairs there are.

His qal vechomer is as follows: Just as the white hair (in a skin blemish), which cannot be redeemed by any other hair (ie: cannot be negated by the presence of a black hair and made clean) is only impure if it was turned white by the blemish, then how much moreso should a thin, yellow hair (in a head/beard blemish), which is redeemed by other hair (ie: is negated by the presence of black or red hairs and made clean), only be considered impure if it was turned thin and yellow by the blemish!

In his lashon, "מה אם שער לבן שאין שער אחר מציל מידו אינו מטמא אלא הפוך, שער צהֹב דק ששער אחר מציל מידו אינו דין שלא יטמא אלא הפוך".

I do not understand what could possibly be the relationship between a hair's being changed by the blemish rather than predating it, and its being "saved", so to speak, by other hairs (ie: negated by their presence and made clean). Furthermore, I do not understand why one of these cases should necessarily be more stringent than the other. Is the skin blemish more stringent because no amount of black hair can purify it? Or is the head/beard blemish more stringent because black and red hair can purify it?

If somebody understands this qal vechomer and how it serves as a proof, I would appreciate an explanation. (I would also appreciate any reference to mefarshim who either explain it or find it problematic.)

2 Answers 2


I've never learned the mishna (or maseches) in question, and am basing this solely on your description and my experience with kal-vachomer arguments elsewhere in Shas. With that caveat:

The argument seems to be this: white hair, which easily renders a person tame (namely, even in the presence of other hair), nonetheless fails to render a person tame unless it followed its blemish. Thus, yellow hair, which hardly renders a person tame (namely, not in the presence of other hair), should a fortiori fail to render a person tame unless it followed its blemish. So all four parts of the argument (white vs. yellow and absence of other hair vs. appearance before the blemish) are about how easily various hairs render a person tame.


The first verse is about a hair being changing. It is a case that an event occurred, like an illness. Torah describes the phenomenon and do not addresses the issues of relationship with any "mechanism".

וְרָאָה הַכֹּהֵן אֶת הַנֶּגַע בְּעוֹר הַבָּשָׂר וְשֵׂעָר בַּנֶּגַע הָפַךְ לָבָן וּמַרְאֵה הַנֶּגַע עָמֹק מֵעוֹר בְּשָׂרוֹ נֶגַע צָרַעַת הוּא וְרָאָהוּ הַכֹּהֵן וְטִמֵּא אֹתוֹ
רש"י ושער בנגע הפך לבן. מתחלה שחור והפך ללבן בתוך הנגע. Rashi says that it was already a hair at this emplacement, and he remained after the apparition of the Vitiligo[1] and the hair color changed to white.

Up to now, we understand the literal sense. Here let's study the Drashas Hasifra,

"בנגע הפך לבן" - לא הקודם. מיכאן אמרו: אם בהרת קדמה לשיער לבן טמא ואם שיער לבן קדם לבהרת טהור ואם ספק טמא. If the vitiligo appears before the white hair, impure, if the white hair appears, before, pure...(this is a new case)

Now we need to examine the verse about the Tinea[1].

וְרָאָה הַכֹּהֵן אֶת הַנֶּגַע וְהִנֵּה מַרְאֵהוּ עָמֹק מִן הָעוֹר וּבוֹ שֵׂעָר צָהֹב דָּק וְטִמֵּא אֹתוֹ הַכֹּהֵן נֶתֶק הוּא צָרַעַת הָרֹאשׁ אוֹ הַזָּקָן הוּא:


ובו שער צהוב. שנהפך שער שחור שבו לצהוב

The hair that was in this place before the tinea appears become yellow and thin, Tame.

But if the ear is surrounded or accompanied by black hair(s). there is no Tum'a.

וְכִי יִרְאֶה הַכֹּהֵן אֶת נֶגַע הַנֶּתֶק וְהִנֵּה אֵין מַרְאֵהוּ עָמֹק מִן הָעוֹר וְשֵׂעָר שָׁחֹר אֵין בּוֹ וְהִסְגִּיר הַכֹּהֵן אֶת נֶגַע הַנֶּתֶק שִׁבְעַת יָמִים

The torah specify this, the black hair is a sign of purity in tineas.
Rabbi Shimeon goes to a conclusion about the "semiologic validity" of both.

  • At the level of the literal sense
    • White hair in vitiligo has a strong validity because you should not verify the lake of black hairs in the proximity
    • Yellow thin hair in tinea has a weak validity because we require a second condition, the lake of black hair.
  • At the level of the Drasha

    • A white hair was here on healthy skin, after time the skin develop a vitiligo. There is no Tum'a.
    • A Yellow and thin hair was here on healthy scalp, after time, the scalp develops a tinea. Here is the discussion.

Now we are ready for the Qal Vachomer

If in matter of presence of dark hair, the white hair remain a valid sign, (and this, despite that he may not be a sign when he was here prior the injury of the skin), a yellow thin hair that was a weak sign, altered by the presence of dark hair, QAL VACHOMER, that he loses his propriety of sign when he precede the injury of the scalp. The strength of a sign is measured by its degree of "pathognomony". Semiology is different than pathophysiology, thus the reasoning is only about the sign strength, and we measure this following the result.

We know that Tsaraat is a set of phenomenons

, in skin, clothes, walls. No "chemical" common denominator. We see this phenomenologically.
And thus the OP is solved. The OP is a "physiologic question" and the Tsaraat is linked to a phenomenological thought. Several things bear some resemblance. Chazal address the issue of a causal relationship with misconducts: the necessity of Teshuva.

[1] I use intentionally a medical terms, for semiologic clarity.

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