as one does not derive a halakha in a lenient case from the halakha in a more stringent one in a manner that would cause one to be stringent in the more lenient case. Since the case of a leper is more stringent than that of a nazirite, as a leper must shave his entire body, one cannot derive from the halakhot of a leper that a stringent halakha applies to a nazirite. It is therefore necessary for the verse to specify that a nazirite’s final shaving must be performed with a razor.

Rabbi Yehuda HaNasi says that the term “razor” itself is not necessary to teach that a nazirite’s final shaving must be performed with a razor, as the verse states: “A razor shall not come upon his head until the completion of the days that he vowed naziriteship to God” (Numbers 6:5). This full sentence indicates that the Torah said: After the completion of his term the shaving must be performed only with a razor.

The Gemara comments: Rabbi Yehuda HaNasi claims that the term “razor” indicates that shaving, in this case that of a nazirite after the completion of his term, may be performed only with a razor. If so, the verse should be understood in the same manner with regard to the prohibition of shaving. But if one examines the first part of the verse by itself, isn’t it written: “A razor shall not come upon his head” (Numbers 6:5), and the first tanna, whose opinion Rabbi Yehuda HaNasi does not dispute, derives from this verse that he is prohibited from shaving by other means as well, notwithstanding the explicit mention of a razor.

The Gemara explains that the phrase “shall not come upon his head” teaches that a nazirite may not remove his hair in any manner. As for the mention of razor in this context, it serves to teach that he will violate two prohibitions for this action of using a razor, one for removing his hair and one for doing so with a razor.

§ Concerning a nazirite who shaves his hair, Rav Ḥisda says: With regard to flogging, a nazirite who shaved his hair is flogged for shaving even one hair; with regard to invalidation, i.e., the ritual shaving of his hair at the end of his naziriteship, the shaving is invalidated if he failed to remove two hairs; and as for negating his naziriteship, shaving during his term negates it only if he shaved most of his head. And this applies only if he removed his hair with a razor.

The Gemara asks: This indicates that according to the opinion of Rav Ḥisda, a nazirite who shaved with a razor, yes, he negates thirty days, whereas if he did so with anything else, no, he does not negate days. But isn’t it taught: From where is it derived to include all implements that remove hair, i.e., that a nazirite is liable if he uses any of them? The verse states: “Shall not come upon his head,” meaning in any manner. This indicates that a nazirite must add days to his term of naziriteship even if he shaved with an implement other than a razor. Rather, say that Rav Ḥisda meant: In the manner of a razor. That is, the nazirite negates his naziriteship only if he removes his hair as one does with a razor, without leaving any part of it.

This opinion is also taught in a baraita (Tosefta 4:3): With regard to a nazirite who tore out, uprooted, or pulled out any amount of hair, this negates days of his naziriteship only if he shaved most of his head, and only if he did so in the manner of a razor. Rabbi Shimon ben Yehuda says in the name of Rabbi Shimon: Just as leaving two hairs invalidates his shaving of ritual purity at the end of his term, and the act is considered incomplete, so too, leaving a mere two hairs negates days of his naziriteship, if he shaved during his term.

§ We learned in a mishna there (Nega’im 14:4): Three types of people must shave their hair, and their shaving is a mitzva: A nazirite; and a leper, as it is stated: “And he who is to be cleansed shall wash his clothes, and shave off all his hair” (Leviticus 14:8–9). And the third category is Levites, when they were first sanctified for their service, as it is stated: “And this you shall do to them to cleanse them: Sprinkle the water of purification upon them, and let them cause a razor to pass over all their flesh” (Numbers 8:7). And with regard to all of them, if they shaved with an implement other than a razor, or if they left two hairs uncut, they have done nothing, i.e., they have not fulfilled their obligation.

The Gemara analyzes this mishna. The Master said there: Three types of people must shave and cut their hair, and their shaving is a mitzva. The Gemara asks: This is obvious; after all, doesn’t the Torah command all three to shave? The Gemara answers: The statement of the mishna is necessary, lest you say that the mitzva is due to and aimed at the removal of hair, and therefore even one who applied a depilatory [nasha] to remove his hair has fulfilled his obligation. The mishna therefore teaches us that this is not so, as the mitzva must be performed by shaving.

The mishna further teaches: And with regard to all of them, if they shaved with an implement other than a razor, they have done nothing. The Gemara asks: Granted, with regard to a nazirite the source of this halakha is clear, as it is written: “A razor shall not come upon his head” (Numbers 6:5), which indicates that when he does shave he must do so with a razor. And similarly, with regard to the Levites it is written: “And let them cause a razor to pass over all their flesh” (Numbers 8:7). However, from where do we derive that a leper must be shaved with a razor for his ritual purification?

And if you would say that this halakha is derived from the case of the Levites, as, just as Levites require shaving and their shaving is only with a razor, so too, I will bring the case of a leper, who requires shaving and say that his shaving can likewise be performed only with a razor, then this comparison can be refuted. What is unique about Levites is that they have an extra stringency, in that they require waving of their bodies, i.e., Aaron was required to pick up and wave the bodies of the Levites as part of the ritual of their sanctification (see Numbers 8:11). Will you say the same with regard to a leper, who does not require waving?

Rather, the halakha that a leper must use a razor is derived from the case of a nazirite, who does not require waving either. However, this comparison can also be refuted: What is unique about the nazirite is that his offering requires bread. Will you say the same with regard to a leper, who does not require bread as part of his purification process? Rather, clearly the halakha of a leper is not derived from either one of the above cases, that of the Levites or the nazirite. Therefore, let it be derived from the two of them.

The Gemara elaborates: As stated previously, from which single case can it be derived? If you say it can be derived from the Levites, what is unique about Levites is that they require waving of their bodies. This suggestion can be countered by saying that the case of a nazirite proves that this stringency is not the decisive factor leading to the requirement of a razor, as a nazirite is not waved and yet he must be shaved with a razor. And if you respond: What is unique about the nazirite is that his offering requires bread, one can similarly argue that the Levites prove that this stringency does not lead to the halakha of shaving with a razor, as the offering of the Levites does not require bread and nevertheless they must be shaved with a razor.

And in this manner the derivation has reverted to its starting point. However, at this stage the halakha is derived from a combination of the two sources: The aspect of this case is not like the aspect of that case, and the aspect of that is not like the aspect of this; each case has its own special features. The common denominator is that they require shaving and their shaving is with a razor. Therefore, I will also bring the case of the leper, who requires shaving, and say that his shaving must be with a razor.

Rava of Barnish said to Rav Ashi: And let us refute this derivation in the following manner: What is the common denominator between the Levites and the nazirite? Their common denominator is that