By contrast, the mishna states that the leper must be shaven like a gourd. In accordance with whose opinion is this? It is in accordance with the opinion of Rabbi Akiva, who interprets verses by means of the principle of amplifications and restrictions. As it is taught in a baraita: In the verse: “And it shall be on the seventh day, that he shall shave off all his hair,” the phrase “all his hair” is an amplification. The phrase that follows: “His head and his beard and his eyebrows,” is a restriction. In the final phrase: “Even all his hair he shall shave off,” the verse then amplified again. The verse is therefore an instance of amplification and restriction and amplification, which includes everything.

What does it include? It includes the hair of all of the body. What does it nevertheless exclude? It excludes nose hairs, which do not need to be shaved. Since the mishna presents only the opinion of Rabbi Akiva, it poses no challenge to Rabbi Yishmael’s list.

The Gemara asks: What conclusion was reached about it, i.e., whether ashes may be used instead of dust for the water of the sota? Come and hear evidence from that which Rav Huna bar Ashi says that Rav says: If there is no dust available for the sota water, the priest brings decomposed vegetable matter, and he consecrates the water with it. This indicates that it is permitted to substitute other substances for dust.

The Gemara responds: But that is not so. Decomposed vegetable matter is permitted because it will become dust, but ashes will not become dust.

§ The mishna states: He would take loose dust from underneath the tablet and place it into the vessel with the water, so that the dust would be visible upon the water. The Sages taught (Tosefta 1:8): Three items are required to be seen: The dust of the sota must be visible in the water, the ashes of the red heifer must be visible when placed in the waters of purification, and the spittle of a woman whose husband, who has a brother, died childless [yevama] must be visible. The yavam, brother-in-law of the yevama, is bound by Torah law to marry her, and this bond is dissolved through the ritual of ḥalitza, in which she spits before him in the presence of judges. In the name of Rabbi Yishmael they said: Even the blood of the bird used in a leper’s purification ritual is required to be visible in the vessel.

The Gemara asks: What is the reasoning of Rabbi Yishmael? As it is written with regard to the process of the purification of a leper: “And he shall take the cedar wood, and the hyssop, and the scarlet, and the living bird, and dip them in the blood of the slain bird, and in the running water” (Leviticus 14:51). And it is taught in a baraita: Had the verse stated only the phrase “in the blood,” one might have thought that these items must be dipped only in the blood and should not be dipped in the water at all. Therefore, the verse also states: “In the running water.” If the verse had stated only the phrase “in the running water,” one might have thought they should be dipped only in the water and not be dipped in the blood at all. Therefore, the verse also states: “In the blood.” How can these texts be reconciled? One must bring little enough water so that the blood of the bird will still be recognizable within it. And how much water is this? It is a quarter-log.

And the Rabbis, who do not require that the blood of the bird be visible in the water, how do they understand the verse? That verse is necessary for its own sake, as this is what the Merciful One is saying: Dip the objects both in blood and in water together. The blood need not be visible.

And why does Rabbi Yishmael reject this straightforward understanding of the verse? It is because if this understanding were so, then the Merciful One should have written simply: And dip in them, i.e., dip the cedar wood, hyssop, scarlet wool, and live bird in the blood and water, as the blood and water have already been mentioned beforehand. Why do I need the verse to list explicitly: “And dip them in the blood of the slain bird, and in the running water”? This is to teach that the blood must be recognizable in the water.

And what would the Rabbis respond to this? If the Merciful One had written simply: And dip in them, then I would say the items should be dipped in this liquid separately and in that liquid separately. Therefore, the Merciful One writes: “And dip them in the blood of the slain bird, and in the running water,” to teach that one must mix them together.

And from where does Rabbi Yishmael derive that one must mix them together? Another verse is written: “And he shall slaughter one of the birds in an earthen vessel over running water” (Leviticus 14:50). This indicates that the blood of the bird must fall directly into the water below, and the blood and the water will become mixed together.

And why do the Rabbis not learn it from that verse? If one were to learn it from that verse, I would say that one should slaughter the bird adjacent to the vessel holding the water, and one should grasp the opened veins to ensure that no blood escapes immediately and then collect the blood in a different vessel. The blood and water would therefore be in separate vessels. Therefore, this first verse teaches us that the blood and water must be mixed together.

Rabbi Yirmeya raised a dilemma before Rabbi Zeira: If the bird is big and contains such a large amount of blood that it effaces the water, rendering it indistinguishable, or if the bird is small and contains so little blood that its blood is effaced due to the water and indistinguishable, what is the halakha?

Rabbi Zeira said to him: Haven’t I told you not to take yourself out of the bounds of the practical halakha? Do not ask questions about impossible eventualities. The Sages measured the ratio of blood to water specifically with regard to a sparrow. There is no sparrow big enough to efface the water, nor is there one small enough to be effaced due to the water.

§ The Rabbis taught (Tosefta, Para 6:6): If one places the dust in the vessel before the water, the mixture is unfit; but Rabbi Shimon deems it fit. The Gemara asks: What is the reasoning of Rabbi Shimon?

It is as it is written with regard to the red heifer: “And for the unclean they shall take of the dust of the burning of the purification from sin, and running water shall be put thereto in a vessel” (Numbers 19:17). And it is taught in a baraita that Rabbi Shimon said: Is it dust [afar] that is taken? But isn’t it really ashes [efer]? Evidently the Torah altered its usage and referred to ashes as dust in order to derive a verbal analogy from it. Dust is stated in the verse here, and dust is stated there, with regard to the sota. Just as there, with regard to the sota, the verse teaches that the dust must be placed on top of water, so too here, with regard to the red heifer, one learns that the dust, i.e., ashes, must be placed on top of the water.

And likewise, just as here, with regard to the red heifer, if one places the dust in the vessel before the water, it is fit after the fact, so too there, with regard to the sota, if one places the dust in the vessel before the water, it is fit.

The Gemara asks: And there, with regard to the red heifer, from where do we derive that the mixture is fit even if the dust is placed first? Two phrases are written in the verse. It is written that the water must be put: “Thereto.” Therefore, apparently, the ashes should be placed first. And it is written that the running water must be placed: “In a vessel.” Apparently, the water should be placed in the vessel first, while it is still empty. How can these texts be reconciled? If he desires to place the water first he places it, and if he desires to place the ash first he places it.

And how do the Rabbis, who deem the mixture unfit, interpret the verse? The verse states: “In a vessel,” specifically. The water must be placed first. When the verse states: “Thereto,” it teaches only that it is required to mix the ashes with the water.

The Gemara asks: But one could just as easily say the opposite: “Thereto” should be understood specifically, and the ashes must be placed first. The phrase “running water shall be put…in a vessel,” should indicate only that the water must run directly into the vessel and that it may not be brought from the spring by means of another vessel.

The Gemara answers: Just as we find in every instance that the facilitating item goes above the primary item, e.g., in the case of a sota the dust goes on top of the water, so too here, in the case of the red heifer, the facilitating item must go above the primary item. The water must be placed first, and only then the ashes.