1) CUTTING A KOHEN'S HAIR
QUESTION: The Gemara teaches that a Kohen is not allowed to grow his hair for more than 30 days. This prohibition is derived through a Gezeirah Shavah from the laws of Nazir. One verse (Bamidbar 6:5) says that a Nazir must let his hair grow "Pera" (uncut), and another verse (Yechezkel 44:20) says that a Kohen may not let his hair grow "Pera" (uncut). This Gezeirah Shavah teaches that just as a Nazir is not allowed to cut his hair for 30 days, a Kohen is not allowed to let his hair grow for 30 days.
The Gemara asks that perhaps the verse in Yechezkel ("... and uncut hair they may not grow") means that the Kohen may not grow his hair at all ("Lo Lirbu Klal").
How can the Gemara make such a suggestion? The Gemara has just stated that a Gezeirah Shavah teaches that the Kohen is allowed to grow his hair for 30 days!
(a) RASHI (according to the corrected version of the Girsa, according to which the word "b'Chol" should be "b'Chaf-Tes," as the Menachem Meshiv Nefesh points out) and TOSFOS answer that the Gemara does not mean to ask that the Kohen must cut his hair everyday. Rather, the Gemara means to ask that perhaps the Kohen is not allowed to grow his hair for 30 complete days, but only for 29 days, and he must cut his hair on day 30.
This approach explains the Gemara's question within the context of the Gezeirah Shavah. However, the Gemara explicitly asks that the Kohen should not be allowed to grow his hair "at all" ("Klal"), which clearly implies even for 29 days. The BACH therefore suggests that the word "Klal" must be deleted from the text of the Gemara.
However, there is no record of such a Girsa in the Rishonim, and no such Girsa is cited by the Dikdukei Sofrim.
(b) The CHESHEK SHLOMO quotes his brother, the MAR'EH KOHEN, who says that according to Rashi and Tosfos the text of the Gemara should read, "Kol Lamed" -- "all 30 days," instead of "Klal" (that is, the letters Kaf-Lamed-Lamed were accidentally placed together by the printer, and they should be separated to read "Kol L'"). Thus, the Gemara is asking that perhaps the Kohen is not allowed to let his hair grow for a complete 30 days, as Rashi and Tosfos explain.
(c) RAV YEHUDAH LANDY suggests another way to explain the Gemara according to Rashi and Tosfos. When the Gemara asks that the Kohen should not grow "it" at all, it does not mean that he should not grow "his hair" at all. Rather, it means he should not grow "Pera" at all. What is "Pera"? "Pera" refers to hair that has grown for a period of 30 days. Thus, the Gemara is asking that perhaps the Kohen is not allowed to grow his hair for 30 days (Pera), but he must cut his hair after 29 days (and not let it grow for 30, which would be Pera, and then cut it). The Gemara answers that the verse implies that the Kohen may grow Pera, but he must cut it immediately after it reaches the stage of Pera.
(d) The CHIDUSHEI HA'RAN in Sanhedrin (22b) and the KEREN ORAH here explain that the Gezeirah Shavah is not a real Gezeirah Shavah. The verse which says that Kohanim may not let their hair grow is a verse in Yechezkel. A Gezeirah Shavah from a verse in the Torah to a verse in Nevi'im is not a real Gezeirah Shavah (see Chagigah 10b). It is only a "Giluy Milsa." Therefore, Abaye asks that since it is not a real Gezeirah Shavah there is no imperative to learn anything from the laws of Nazir. Consequently, the Gemara asks that perhaps a Kohen may not grow his hair at all (literally) and he must shave his head every day.