The strip of crimson of the red heifer has the weight of ten zuz; and the strip of the scapegoat has the weight of two sela, which is eight zuz; and the strip of the leper has the weight of a shekel, which is two zuz.

And Rabbi Yoḥanan further said: Rabbi Shimon ben Ḥalafta and the Rabbis disagree with regard to the strip of crimson of the red heifer. One said: It has the weight of ten zuz. And one said: It has the weight of one shekel. And your mnemonic for remembering that while both assume that only one of the extreme values was required no one suggests the middle value of two sela is required, is the aphorism from a mishna: God equally values both the one who gives much and the one who gives little as long as his intention is to Heaven.

Rabbi Yirmeya of Difti said to Ravina: It is not with regard to the strip of the red heifer that they disagree; rather, it is with regard to the strip of the scapegoat that they disagree. And on that very day that they disputed this issue, Ravya bar Kisi died, and they made a mnemonic out of it, associating the halakha with his name: The death of Ravya bar Kisi atones like the scapegoat, since the death of the righteous person atones for his generation.

Rabbi Yitzḥak said: I heard a teaching that there is a distinction between two slaughters: One of the red heifer, and one of the bull of the High Priest on Yom Kippur. The slaughter of one of them is valid even if done by a non-priest, and the slaughter of the other one is invalid if done by a non-priest. But I do not know which of them is which.

An amoraic dispute was stated: With regard to the slaughter of the red heifer and the bull of the High Priest on Yom Kippur, there is a dispute between Rav and Shmuel: One said: A red heifer slaughtered by a non-priest is invalid, whereas the bull of the High Priest slaughtered by a non-priest is valid. And the other one said: His bull is invalid, but the red heifer is valid.

The Gemara comments: Conclude that it is Rav who said that if the heifer is slaughtered by a non-priest it is invalid, as Rabbi Zeira said: The slaughter of the heifer by a non-priest is invalid. And Rav said concerning this statement of Rabbi Zeira: This is because we learned in the Torah’s description of the slaughter of the red heifer both “Elazar the priest” (Numbers 19:3) and “statute” (Numbers 19:2). Because Elazar is mentioned, it indicates the slaughter should be performed by a priest, and the use of the term “statute” teaches that one may not deviate from any of the details of the service as delineated in the verses; if one does deviate, the service is invalid. Clearly then, Rav held that if the heifer is slaughtered by a non-priest it is invalid.

The Gemara analyzes Rav’s opinion: And according to Rav, what is different with regard to the red heifer, that if it is slaughtered by a non-priest it is invalid? As Rav explained, it is different in that, with regard to it, it is written “Elazar” and “statute.” But with regard to the bull of the High Priest it is also written “Aaron” the High Priest (Leviticus 16:11) and “statute” (Leviticus 16:34). Based on Rav’s logic, that indicates that the priest is indispensable.

The Gemara explains: The slaughter of the bull by a non-priest is valid because slaughtering is not classified as a sacrificial service; therefore, it does not have to be done by a priest. The Gemara challenges this answer: If so, by the same logic, the red heifer should also be valid when slaughtered by a non-priest. The Gemara concludes: The logic that slaughtering is not classified as a sacrificial service does not apply in the case of the red heifer because the red heifer is different. It has the sanctity of items consecrated for Temple maintenance, and therefore the principles that apply to other offerings do not necessarily apply to it.

But is it not arguable, by an a fortiori inference, that the slaughter of the red heifer by a non-priest is valid? If the slaughter of the bull of the High Priest, which is an actual offering, is valid when performed by a non-priest, then all the more so the slaughter of the red heifer, which is not an offering, should be valid when similarly performed by a non-priest. Rav Shisha, son of Rav Idi, said: The slaughter of the red heifer by a non-priest is invalid. The halakha is just as in the case of appearances of leprosy, which, despite their not being a sacrificial service, still require the priesthood. Only a priest may declare the signs of leprosy to be pure or impure. It is apparent from this case that the logic of the a fortiori inference does not hold.

The Gemara analyzes Shmuel’s opinion: And according to Shmuel, who said that if a non-priest slaughters the bull of the High Priest it is invalid, what is different with regard to his bull that this is the halakha? It is different in that, with regard to it, it is written “Aaron,” indicating that a priest is required, and “statute,” indicating that the requirements of the Yom Kippur service are indispensable. But with regard to the red heifer it is also written: “Elazar” and “statute” which by the same logic should indicate the need for a priest is indispensable. The Gemara concludes: It is different there as it is written: “And he shall slaughter it before him” (Numbers 19:3), i.e., in front of Elazar, which suggests that it could be that a non-priest slaughters and Elazar watches.

And Rav, who assumes the slaughter is performed by the priest himself, how does he interpret the phrase: “Before him”? He understands it to mean that he should not divert his attention from the heifer from the moment of slaughtering until the completion of the process. As with other matters of purification, one is required to maintain his attention on the matter; any distraction can invalidate the process. And from where does Shmuel, who already derived something from this verse, derive that he should not divert his attention from it? He derives it from the verse: “And he shall burn the heifer in his sight” (Numbers 19:5).

And what does Rav learn from this verse? He holds that one verse is needed to teach the requirement to maintain one’s attention with regard to slaughtering, and one verse is needed to teach the requirement with regard to burning.

And it is necessary to have the requirement stated in both cases since, if the Merciful One had written it only with regard to slaughtering, I might have limited the requirement to that case because it is the start of the Temple service; but with regard to burning, I could say that no, there is no requirement. Therefore, it is necessary to teach the requirement also in the case of burning. And if the Merciful One had written the requirement only with regard to burning, I might have limited it to that case, because it is now that the heifer is actually being made ready to be used; but with regard to slaughtering, I could say that no, there is no requirement. Therefore, it is necessary to teach the requirement also in that case.

As the requirement is mentioned with regard to two stages of the rite of the red heifer, this suggests that it does not exist for every stage. Therefore, the Gemara asks: It is written this way in order to exclude what stage? If we say, to exclude from the requirement the stages of gathering its ashes and filling the water for sanctification, i.e., taking the water in order to pour it on the ashes and mix them together,