Mishnayos Parah Perek 3 Mishnah 1

שבעת ימים כו' מפרישין כהן השורף את הפרה – as it is written in the portion of investment/inauguration [of the Kohanim] (Leviticus 8:34): "כאשר עשה ביום הזה צוה ה' לעשת לכפר עליכם"/”Everything done today, the LORD has commanded to be done [seven days], to make expiation for you,” and our Rabbis/teachers expounded (see Talmud Tractate Yoma 2a): "לעשת" /to be done – this is the act of the [Red] Heifer, "לכפר עליכם"/to make expiation for you – this is the act of Yom Kippur. That the Kohen who burns the heifer and the High Priest/Kohen Gadol who serves on the Day of Atonement requires separation for seven days] like Aaron and his sons would require in the seven days of investment/inauguration, as is written (Leviticus 8:33): “You shall not go outside the entrance of the Tent of Meeting for seven days,” And they would separate him from his wife, lest he come upon his wife and she would be found to be a menstruant woman and someone who has sexual relations with a menstruant woman is impure for seven days and is not able to burn the cow/heifer.

הבירה – there are those that say that this place was on the Temple Mount and “Birah” was its name. But there are those who say that the entire Temple is called “Birah,” as it states (I Chronicles 29:19: “[As to my son, Solomon, give him a whole heart to observe Your commandments, Your admonitions, and Your laws, and to fulfill them all,] and to build this temple for which I have made provision.”

צפונה מזרחה – the reason that they separate the Kohen who burns the Heifer/cow to a chamber that is in the northeast, since it is a sin offering [being offered] and the sin-offering requires the north (see Numbers 19:9), the Rabbis established for him in the northeast just that there will be for him recognition.

ובית אבן היתה נקראת – because all of its acts were with vessels of untrimmed stone, vessels of stone and vessels of earth that are not susceptible to receive defilement, and in them alone he would use all seven of the days of separation, because someone who is a person who immersed himself that day/טבול יום is fit/kosher [to offer up] the heifer, and they would defile the Kohen that burns the heifer and would immerse him immediately to remove (the false opinion) out of the heart of the Sadducees (i.e., to demonstrate, by practice, the rejection of their opinion) who state that it was done at sunset, the Rabbis established for it extra preference so that they would not disregard/despise it.

כל שבעת הימים – of the days of separation.

מכל חטאות שהיו שם – all the heifers that were made from the days of Moses our Teacher/Rabbi and until that time. For each and every Red Heifer that they would give a bit for protection, and on the first day they would sprinkle upon him from the ashes of one heifer and on the second day from another and the third day from another.

בשלישי ובשביעי – [on the third and seventh days] of his separation. And between the first Tanna/teacher and Rabbi Yossi, both of them hold that immersion at its appropriate time is a Mitzvah, but they differ with regard to sprinkling if they make an analogy to immersion or not, the first Tanna/teacher makes an analogy between sprinkling and ritual immersion and sprinkling at its appropriate time is a Mitzvah, and each day from the first seven days there is doubt lest today is their third day of his defilement, and the three concluding days – each day we have doubt that perhaps it is the seventh [day]. But on the fourth [day], it does not require sprinkling, for it is not on the third [day], one can doubt, but one cannot doubt on the seventh [day], for the sprinkling on the seventh [day] does not count because sprinkling on the seventh [day] until he actually sprinkled on the third [day] that is prior to it. And all of the seven [days] are not exclusively, for perforce we hold that sprinkling is שבות /a rabbinic degree to enhance the character of the Shabbat as a day of rest, and does not supersede the Sabbath. But Rabbi Yossi does not make an analogy between sprinkling and ritual immersion, and sprinkling at the appropriate time is not a Mitzvah, therefore, he doesn’t require sprinkling other than on the third and on the seventh [days] alone. But Rabbi Hanina the Prefect of the Kohanim also holds like Rabbi Meir, that sprinkling at its appropriate time is not a Mitzvah, and the Kohen who burns the Heifer is a mere preference, just as they would not disregard/despise it because it is done with a person who is immersed himself that day/טבול יום.