1)

(a)According to Rebbi Eliezer, the Isur of destroying one's beard incorporates any form of destruction, as we just learned. And he learns from the Pasuk ...

1. ... "Ta'ar Lo Ya'avor al Rosho - that a Nazir is forbidden to shave with a razor (exclusively - like Rebbi Yonasan on Daf 39b).

2. ... "Yegalach es Kol Se'aro, es Rosho es Z'kano" - that a Metzora who is also a Nazir is nevertheless obligated to shave his hair with a razor.

(b)What induces him to make this Derashah - is the fact that the Torah has already written "es Kol Se'aro", in which case "es Rosho" and "es Zekano" appear redundant.

(c)Rebbi Eliezer's opinion is based on the fact that a Nazir only transgresses if he shaves with a razor (like Rebbi Yonasan above); whereas the Rabanan hold that he transgresses even if he destroys his hair in some other way (like Rebbi Yoshiyah), in which case they cannot learn from here that a Metzora is obligated to shave using a razor.

2)

(a)We ask on Rebbi Eliezer that perhaps "Rosho" comes to permit the Metzora to shave with a razor, and not to obligate him (like we asked above on the Rabanan) - to which we give the second of the previous answers; namely, the principle of Reish Lakish would not then permit him to use a razor.

(b)We deliberately avoid presenting the first answer that we gave there (that we would then learn this from a 'Kal va'Chomer' from Nazir who is not a Metzora, who did not perform a sin) - because a Nazir would only contravene one Lav, whereas a Metzora would contravene two.

3)

(a)The Rabanan (who learn the obligation to shave the Metzora from "Zekano") learn from "Rosho" - that the Mitzvah of shaving overrides the sin of cutting off the Pe'os.

(b)In spite of the fact that the Torah has already written ...

1. ... "Zekano", it still needs to write "Rosho" - because we would otherwise have thought that someone who shaves off all the hair of his head does not contravene the Lav of cutting off one's Pe'os, and it is not therefore necessary to mention it (since it is included in "Yegalach es Kol Se'aro"). So by writing Rosho, the Torah comes to teach us that 'Hakafas Kol ha'Rosh Shmah Hakafah' (shaving off all the hair of one's head is generally a contravention of the Lav of cutting one's Pe'os), which the Torah is permitting here.

2. ... "Rosho", it still needs to write "Zekano" - because from "Rosho" we learn that a. 'Hakafas Kol ha'Rosh Shmah Hakafah'; b. the Lav of cutting one's Pe'os is rescinded due to 'Aseh Docheh Lo Sa'aseh', but we would not know that one requires a razor. That we learn from "Zekano".

(c)We would not otherwise have known that a razor must be used to shave - because one contravenes the Lav of cutting the Pe'os irrespective of what one uses ('k'Ein Ta'ar' incorporating scissors).

4)

(a)The Mitzvah of shaving the head of a Nazir who is a Metzora overrides - two Lavin ("Ta'ar Lo Ya'avor al Rosho" and "Lo Sakifu ... ") and an Aseh ("Gadel Pera .... ").

(b)We might know that the Aseh of shaving of a Metzora overrides all three from the Limud of "Rosho", which is all-embracing (though this appears to clash with what we learned earlier). Alternatively - we might also know it from the Limud of "Zekano", which overrides the Lav and the Aseh of Kohanim (as we learned above), and there is no Sevara to differentiate between one Lav and an Aseh and two Lavin and an Aseh.

(c)We attempt to resolve this with the fact that the Lav and the Aseh of Kohanim, which "Zekano" comes to override, do not pertain to everyone, whereas the Lavin and the Aseh of a Nazir who is a Metzora that are being overridden by "Rosho" do (and we cannot learn what is 'Shaveh b'Kol', in this regard, from what is not) - by pointing out that the latter (which are confined either to a Nazir or to men) are not 'Shaveh ba'Kol' either (though the Gemara in Perek 'Shnei Nezirim' seems to say otherwise [see Orach Mishor]).

(d)According to Rebbi Eliezer, who learns from "Rosho" that the Mitzvah to shave overrides the Lav and the Aseh of a Nazir who is a Metzora, the Torah needs to write "Zekano" (we cannot learn that the Mitzvah overrides the Lavin and the Aseh of Kohanim from the Limud of "Rosho") either because the Isurim of a Nazir are more lenient than those of Kehunah or because the Isurim of Kehunah are more stringent than those of Nazir. The Isurim of ...

1. ... a Nazir more lenient than those of Kehunah - inasmuch as they can be revoked.

2. ... Kehunah more stringent than those of Nazir - inasmuch as the Torah gave the Kohanim more Mitzvos.

5)

(a)We just learned that the Rabanan learn 'Aseh Docheh Lo Sa'aseh' from "Rosho" (of Metzora). Rebbi Eliezer (who uses "Rosho" to obligate the Metzora to shave with a razor), learns 'Aseh Docheh Lo Sa'aseh' - from the juxtaposition of "Gedilim Ta'aseh Lach" to "Lo Silbash Sha'atnez" (in Ki Setzei), permitting Sha'atnez in Tzitzis (i.e. woolen [blue threads of] Tzitzis on a linen garment).

(b)He cannot learn it from the fact that the shaving of a Metzora overrides the Lav of ...

1. ... Hakafah of Kohanim - because the latter is not 'Shaveh b'Kol'.

2. ... Nazir - because the Isur can be revoked.

(c)To reconcile our Sugya, where the Rabanan learn 'Aseh Docheh Lo Sa'aseh' from "Rosho" with the Sugya in Yevamos, where they learn it from "Gedilim", we establish that the latter learns 'Hakafas Kol ha'Rosh Shmah Hakafah' from "Rosho" (in which case the Pasuk is not redundant to learn from it 'Aseh Docheh Lo Sa'aseh'); whereas our Sugya, where the Rabanan learn 'Aseh Docheh Lo Sa'aseh' from "Rosho" - holds that 'Hakafas Kol ha'Rosh Shmah Hakafah' is a Sevara (like the Sugya in 'Shnei Nezirin').