Parah, Chapter 3, Mishnah 1. Having dealt with the qualifications of the cow herself, the Mishnah now turns to the preparations made for the actual service of burning her. Everything here revolves around a single concern: the kohen who performs this avodah must be brought to a state of taharah so secure that no doubt can be raised about him.
Seven Days in the Beis Even
The Mishnah's opening ruling sets a timetable. A full week ahead of the day set for burning the cow, "shiv'as yamim" before the "sreifas haparah," the kohen designated for that avodah is taken out of his household, "mafrishin" him "mibeiso," and lodged in a chamber of the Mikdash. Its position is given precisely: "al penei habirah," opposite the birah, at its northern-eastern side, "tsefonah mizrachah." That chamber carried a name of its own, "Beis Even," the House of Stone.
He does not simply pass the week in idleness there. Purifying water is applied to him repeatedly: "umazin alav" on each of the "shiv'as hayamim," and the water used is taken "mikol chatas" that was in storage in that place, that is, from every one of the batches of mei chatas kept on hand there.
How Many Days of Sprinkling?
Rabbi Yose does not accept that description of the practice. In his opinion the water was applied on two days only, "bashlishi uvashvi'i bilvad," the third day and the seventh. On the remaining days, "lo hayu mazin alav" at all.
Rabbi Chanina, the segan hakohanim, deputy to the kohanim and therefore intimately familiar with how things were actually run in the Beis Hamikdash, settles the matter by separating two different cases. For the kohen appointed to burn the parah adumah, "mazin kol shiv'as yamim": the sprinkling extended over the whole week. But for the kohen being readied for the avodah "shel Yom Hakippurim," the water was applied on two days only, "bashlishi uvashvi'i bilvad."
Why Yom Kippur Belongs in This Discussion
Yom Kippur enters the picture because the pasuk that commands this preparation speaks of both services at once. The Torah's words, that the Kohen Gadol is to "do" and to "make atonement for you," are understood so that la'asos, to do, points to the service of the parah adumah, while lechaper, to make atonement, points to the service of Yom Kippur. Both avodos therefore require that the kohen be set apart in advance and purified.
The difference between them, as Rabbi Chanina segan hakohanim spells out, lies in the sprinkling: for the parah adumah the mei chatas is applied on all seven days, while for Yom Kippur it is applied on the third day and on the seventh day alone.