Parah, Chapter 2, Mishnah 5. This chapter takes up the many details that can disqualify a parah adumah, and here the Mishnah returns to the requirement that the cow be entirely red. The question before us is what happens when hairs of another color are found on her: how many are too many, and does it matter where on her body they are located?
Two Hairs in a Single Pore
Our Mishnah opens with a narrow case. "Hayu bah shtei se'aros", there were upon her two hairs, "shechoros o levanos", whether of black or of white, "besoch gumah achas", sprouting from one single pore: "pesulah", and she may not be used.
Rabbi Yehudah broadens the ruling: "Afilu besoch kos echad." The hairs of an animal lie along its body in little circlets, something like curls, and each such circlet is called a kos, a hollow. Rabbi Yehudah holds that two black or white hairs found inside a single circlet disqualify the cow even though they are not emerging from one single pore. In other words, where the first Tanna speaks of a pore, Rabbi Yehudah speaks of a kos. The two terms may sound like one another, and this is precisely the point of dispute: is the measure the pore itself, or a small defined area that may well contain more than one pore?
The Mishnah then presents a second situation. "Hayu besoch shenei kosos", the two hairs sat in two different circlets, "vehein mokhichos", and yet they give evidence, "zo es zo", each one about its fellow: their arrangement reveals them to be a matched pair and not a stray hair here and a stray hair there. In such a case as well, the animal is disqualified.
How Many Hairs May Be Plucked?
Rabbi Akiva rules with striking leniency. "Afilu arba, afilu chamesh", a count of four such hairs, or a count of five, "vehein mefuzaros", when they sit far apart from one another over her body rather than bunched in a single spot, "yislosh", one simply pulls them out, and she retains her fitness.
Rabbi Eliezer stretches the leniency much further: "Afilu chamishim." A full fifty hairs of either shade may be plucked away, so long as they lie scattered here and there across her, and the parah still remains valid for the ashes.
Rabbi Yehoshua ben Beseira takes the opposite tack. "Afilu achas beroshah", even a single hair situated on her head, "ve'achas biznavah", together with one down at her tail: "pesulah", she is rendered unusable. The view is remarkable, since no two places on the animal could stand farther apart than these, and still, to his mind, that pair invalidates her.
Hairs That Are Two Colors
The final case of the Mishnah concerns hairs that are not one solid shade from base to tip. "Hayu bah shtei se'aros", she had two hairs, "ikaran mashchir veroshan ma'adim", darkening at the base while red at the top, or else the reverse situation, "ikaran ma'adim veroshan mashchir", red at the base and darkening at the top. By which portion of the hair is its color determined?
Rabbi Meir rules "hakol holeich achar hanir'eh": everything follows what is visible, meaning the color seen at the top of the hair. The Chachamim disagree and say "achar ha'ikar": we follow the root, the base of the hair, and not the part that meets the eye.
The Halachah
Among all of these views, the halachah follows the opinion of the first Tanna of the Mishnah: two black hairs or two white hairs growing within one single pore render the parah adumah invalid.