one might have thought that even a leper should likewise be prohibited from rounding off his head. The verse therefore specifically states “his head” to teach that the mitzva for a leper to remove all the hair of his head overrides the prohibition against rounding one’s head. And it was taught in another baraita: Why must the verse state: “His head,” with regard to a leper? Since it states, with regard to a nazirite: “No razor shall come upon his head” (Numbers 6:5), one might have thought that even a nazirite leper should likewise be prohibited from shaving upon his purification. Therefore the verse states: “His head,” from which it is derived that a nazirite who contracted leprosy must shave his head like any other leper.

The Gemara explains: What, is it not correct to say that this is a dispute between tanna’im? According to the one who says that the additional term “his head” is to counter a possible prohibition derived from the case of a nazirite, he holds that rounding the entire head is not called rounding, and therefore there is no need for a verse to teach that a leper can shave all the hair off his head. And when the verse “He shall shave all his hair; his head” comes, it comes to override both the prohibition: “No razor shall come upon his head,” and the positive mitzva stated with regard to a nazirite: “He shall be sacred, he shall let the locks of the hair of his head grow long” (Numbers 6:5). And the other tanna holds that rounding the entire head is called rounding, and consequently, when the verse comes, it serves to override only the prohibition against rounding one’s head.

Rava said in refutation of this proof: No; it is possible that everyone agrees that rounding the entire head is not called rounding, even the tanna who maintains that the purpose of the verse is to permit a leper to round his head. And when the verse comes, it serves to address a particular case, such as one in which he rounded off only the corners of the head and ultimately shaved off the rest of his hair. Although shaving only the corners of one’s head is prohibited by the Torah, in this instance he is exempt. The reason is that since if he shaved his entire head at one time he would not be liable, then if he rounded off his head and ultimately shaved he is also not liable. Since a leper is permitted to shave all of his head, he can do so in any manner he chooses.

The Gemara raises a difficulty with this explanation: And does the verse write this? Is it permitted unnecessarily to transgress a prohibition ab initio? But didn’t Reish Lakish say: Any place that you find positive mitzvot and prohibitions that clash with one another, if you can find some way to fulfill both, that is preferable; and if that is not possible, the positive mitzva will come and override the prohibition? If it is not prohibited to round the entire head, the leper can shave his hair in a permitted manner, and the Torah would not have allowed him to do so in a way that involves the violation of a prohibition.

Rather, the Gemara retracts its previous explanation and states the opposite. It is that everyone agrees that rounding the entire head is called rounding. If so, the baraita that states that the verse: “He shall shave all his hair; his head” (Leviticus 14:9), comes to permit the rounding of a leper’s entire head is easily understood, as it is derived from here that a positive mitzva overrides a prohibition. But according to the one who establishes the verse “He shall shave all his hair; his head” as coming to override the prohibition and the positive mitzva of a nazirite, from where does he derive that a positive mitzva overrides only a prohibition?

The Gemara answers: He derives it from the case of ritual fringes. How so? As the verse states: “You shall not wear diverse kinds, wool and linen together” (Deuteronomy 22:11), and it is taught in a baraita that although the command “You shall not wear diverse kinds” applies to most cases, the juxtaposed verse: “You shall make for you fringes” (Deuteronomy 22:12), teaches that one may prepare ritual fringes even from diverse kinds of wool and linen. This teaches that the positive mitzva of ritual fringes overrides the prohibition of diverse kinds.

The Gemara asks: And the tanna who derives the principle that a positive mitzva overrides a prohibition from “his head” stated with regard to a leper, what is the reason that he does not derive it from the verse that deals with ritual fringes? Why does he require another source? The Gemara answers: He could have said to you that the verse concerning ritual fringes does not teach that principle, as it comes for that which Rava said.

As Rava raises a contradiction: It is written: “And that they put on the fringe of each corner a thread of sky blue” (Numbers 15:38). The phrase “the fringe of each corner” indicates that ritual fringes must be of the same type as the corner of the robe itself, upon which they must place “a thread of sky blue.” And yet it is written: “You shall not wear diverse kinds, wool and linen together” (Deuteronomy 22:11). The juxtaposition of these two verses teaches that ritual fringes must be made from wool and linen.

How so? How can ritual fringes be made from the same material as the garment itself and also from wool and linen? The answer is that ritual fringes of wool and linen exempt a garment and fulfill the obligation of ritual fringes whether the garment is of their own type, i.e., wool and linen, or whether it is not of their own type, i.e., all other materials. By contrast, with regard to ritual fringes of other types of materials, they exempt a garment of their own type; but they do not exempt a garment that is not of their type. According to this, the verse juxtaposing ritual fringes to diverse kinds serves to teach that ritual fringes made of wool and linen exempt any garment, not to teach that a positive mitzva overrides a prohibition.

The Gemara continues this line of inquiry: And according to this tanna, who derives from the term “his head” that a positive mitzva overrides only a prohibition, from where do we derive the halakha that the positive mitzva of a leper’s shaving comes and overrides the prohibition and the positive mitzva of a nazirite? From where does this tanna learn that a nazirite who contracted leprosy is obligated to shave? The Gemara answers: He derives it from the verse: “He shall shave all his hair; his head and his beard” (Leviticus 14:9).

As it is taught in a baraita: Why must the verse state: “His beard”? After all, a beard is already included in the phrase “all his hair.” The baraita answers: Since it is stated, with regard to priests: “Neither shall they shave off the corners of their beard” (Leviticus 21:5), one might have thought that even a priest who is a leper is included in this prohibition against shaving his beard. Therefore, the verse states: “His beard” in connection to a leper.

The Gemara asks: And the one who derives from “his head” that the mitzva of shaving overrides both the positive mitzva and prohibition of a nazirite, let him derive this principle from “his beard.” The Gemara refutes this suggestion: And according to your reasoning, that the term “his beard” teaches that a positive mitzva overrides the prohibition and positive mitzva of a nazirite, that which we maintain generally,