1) THE HAIRCUT OF A BALD NAZIR
QUESTION: The Gemara cites a dispute between Beis Shamai and Beis Hillel with regard to a bald Nazir. Beis Shamai maintains that a bald Nazir is not required to pass a razor over his head. Beis Hillel maintains (according to the Gemara's initial understanding, and, according to some Girsa'os, according to the Gemara's conclusion as well) that a bald Nazir is required to hold a razor and pass it over his bald scalp. (See Chart for a summary of the various stages of the Gemara and its two versions according to the different Girsa'os, and for a summary of the entire Sugya based on the Arzei ha'Levanon's explanation and Girsa in Tosfos to 46a.)
According to Beis Hillel, what is the point in having a bald Nazir pass a razor over his head if there is no hair for it to cut? How can such an act constitute Gilu'ach, shaving?
(a) According to the first version in the Gemara (and according to Tosfos' first explanation of the second version), the purpose of passing a razor over the head of the bald Nazir is as follows. When the verse first states that "all the days of his Nezirus a razor shall not pass over his head" (Bamidbar 6:5), and then adds, "... until the completion of the days of his Nezirus," it implies that on the day of the completion of his Nezirus he should pass a razor over his head. (See the Gemara earlier, beginning of 40a, which interprets the verse in such a manner.) According to Beis Hillel, the verse teaches that a Nazir is obligated to pass a razor over his head at the completion of his Nezirus, in addition to the actual obligation to shave. Besides the Mitzvah to shave his hair on the day he completes his Nezirus, there is a Mitzvah to pass a razor over his head.
This seems to be the intention of Beis Hillel according to Tosfos, who writes that according to Beis Hillel the Nazir does fulfill the Mitzvah of Gilu'ach to some extent when he passes a razor over his head. Tosfos compares this case to the case of a Nazir who has no palms, who performs the Tenufah of his Shalmei Nazir and Lachmei Nazir with his arms instead of his palms.
(b) Tosfos, in his second explanation of the second version in the Gemara, implies that passing a razor over the head is not an act of Gilu'ach at all. Tosfos writes that according to Beis Hillel, who maintains that a bald Nazir must pass a razor over his head, the act of Gilu'ach is not Me'akev, and not only may the Nazir drink wine without Gilu'ach but he may bring his Korban as well.
Tosfos understands that passing a razor over the head is not considered an act of Gilu'ach. Why, then, does Beis Hillel require that the bald Nazir pass a razor over his head? One answer is that the requirement to pass a razor over his head is a Halachah d'Oraisa based on the inference from the verse (mentioned above) which teaches that a Nazir must pass a razor over his head at the conclusion of his Nezirus (independent of the requirement to shave). The act, however, does not satisfy the Torah's requirement of Gilu'ach. The Torah requires that he fulfill a separate Mitzvah of shaving his hair, but if he is bald he is exempt from that Mitzvah.
A second answer is that the requirement to pass a razor over his head is mid'Rabanan. The Rabanan enacted that a bald Nazir must pass a razor over his head so that people not mistakenly assume that a Nazir (with hair) is permitted to bring his Korban l'Chatchilah without shaving.
2) AN INVALID "GILU'ACH"
QUESTION: The Mishnah teaches that when a Nazir performed his Gilu'ach with a certain Korban and then discovered that the Korban was Pasul, his Gilu'ach is also Pasul and the remaining Korbenos Nazir which he offered after the first Korban do not count as his Korbenos Nazir.
TOSFOS explains that the reason why the rest of his Korbanos do not count as his Korbenos Nazir is that the Gilu'ach he performed before he offered those Korbanos was invalid. The Gilu'ach was invalid because it was not performed after at least one of his Korbanos was offered (because the Korban turned out to be Pasul). Once he discovers that his Gilu'ach was invalid, he must wait another seven or thirty days (seven according to Rebbi Eliezer, or thirty according to the Rabanan, 16a) to allow his hair to grow back before he is fit to shave again and bring his Korbanos.
The words of Tosfos are difficult to understand.
According to the Rabanan who maintain that the Tiglachas is not Me'akev the Nazir from drinking wine, even if the Nazir does not shave at all his Nezirus ends after he offers the Korbanos. The previous Sugya taught that according to the Rabanan a bald Nazir is not required to do any act of shaving. Why, then, should the Nazir's Korbanos be Pasul simply because he now has no hair to shave (since he shaved all of it off with an invalid Gilu'ach)?
One answer to this question may be that although the Tiglachas is not Me'akev, nevertheless the Nazir at least must have hair that is fit to be cut at the time he brings his Korbanos (see Insights to 39a). Now that his hair is entirely shaved, he cannot perform Tiglachas. Although a bald Nazir is not required to have hair in order to complete his Nezirus, a Nazir whose hair is able to grow must have hair fit for Tiglachas in order to be able to offer his Korbanos. For this reason, a Nazir must observe an additional thirty days of Nezirus if all of his hair was cut off on the last day of his Nezirus.
However, this answer is unsatisfactory. It should suffice for the Nazir to have hair fit to be cut at the time of the completion of his Nezirus. Even if his hair is cut at that point (before he offers his Korban), he should not be required to wait until his hair grows back to perform another Gilu'ach and bring his Korbanos. Although the Gemara earlier (39b) says that he must wait a number of days (seven or thirty) so that his hair grows back, Tosfos writes that the Nazir's requirement to wait days of Gidul Se'ar (growing hair) when his hair was cut after the completion of his Nezirus but before his Tiglachas is only mid'Rabanan (see Insights to 39a). Consequently, mid'Oraisa he may bring his Korbanos immediately after his invalid Gilu'ach and he does not need to wait seven or thirty days. Why, then, should the Korbanos which he brings after the Gilu'ach be Pasul mid'Oraisa? If they are Pasul only mid'Rabanan, why is he permitted to bring another Korban Chatas afterwards? Such a Korban will be Chulin ba'Azarah! (KEREN ORAH, BIRKAS ROSH)
ANSWER: Since the Nazir intended to fulfill the Mitzvah d'Rabanan -- of offering Korbanos with Tiglachas -- which applies to a Nazir whose hair was cut after "Melos" (the conclusion of his Nezirus), the Korbanos which he offered under the assumption that he had fulfilled the Mitzvah are not valid. It is as though he offered his Korbanos on condition that they serve as his Korbenos Nazir only if he fulfills the Mitzvah in the proper way. He has in mind that they should not serve as his Korbenos Nazir if he does not fulfill the Mitzvah in the proper way, so that he may properly fulfill the Mitzvah d'Rabanan of Tiglachas with Korbanos later when his hair grows back.
Alternatively, since a person offers his Korbanos according to the will of the Rabanan ("a'Da'ata d'Rabanan"), the Rabanan are able to render his Korbanos invalid by ascribing to his action the intention that the Korban should not serve as his Korban Nezirus, as Tosfos writes in Sukah (3a, DH d'Amar) with regard to the case of a person who sits in a Sukah which is Pasul mid'Rabanan.