SUMMARY: The Mishnah cites the dispute between Rebbi Eliezer and the Chachamim with regard to a Nazir who becomes Tamei at the end of his Nezirus. The Chachamim rule that when one accepts Nezirus (for an unspecified period) and on the last day (day 30) of his Nezirus he becomes Tamei, he loses all 30 days and must observe them again after he becomes Tahor. According to Rebbi Eliezer, becoming Tamei on day 30 does not cause him to lose any days; he merely must wait until he becomes Tahor and then he may bring his Korbanos.

In the next case of the Mishnah, a person accepts Nezirus for 100 days and becomes Tamei on day 100. The Chachamim rule that he loses the entire Nezirus and must recount all 100 days, since he became Tamei before he completed the Nezirus. Rebbi Eliezer maintains that he must repeat only 30 days of his Nezirus. The Gemara explains that Rebbi Eliezer derives his view from the verse that teaches that a Nazir who becomes Tamei on the last day of his Nezirus does not lose his entire Nezirus, but only 30 days.

The Mishnah then states that if the Nazir becomes Tamei on day 101 (the day on which he is supposed to bring his Korbanos), according to the Chachamim he loses 30 days, and according to Rebbi Eliezer he loses nothing (he merely waits seven days until he becomes Tahor and then he brings his Korbanos; see Chart #1).

The Gemara earlier (6a) discusses at length the reasons for the opinions of Rebbi Eliezer and the Chachamim, and the Gemara here discusses their reasoning in brief. In order to clarify the main points of the Sugya, a basic question needs to be addressed:

Why do the Chachamim rule that a Nazir who becomes Tamei on day 30 loses his entire Nezirus? The Halachah is that "Miktzas ha'Yom k'Kulo," and therefore the beginning of day 30 should be considered the completion of the Nezirus. The end of day 30 is after the Nezirus has completed, when he is already eligible to bring his Korbanos. Why does he lose all 30 days?

This question applies according to the view of Rav Masna who rules that Nezirus is 30 days and "Miktzas ha'Yom" is "k'Kulo." It may also be asked according to the view of Bar Pada who disagrees with Rav Masna and says that "Miktzas ha'Yom" is not "k'Kulo" and that an ordinary Nezirus is only 29 days. If Stam Nezirus is only 29 days, a Nazir who becomes Tamei on day 30 should lose none of his Nezirus because day 30 is after his Nezirus has ended.

This question certainly applies to the Chachamim's ruling in the last case of the Mishnah, in which a person accepts a 100-day Nezirus and becomes Tamei on day 101. The Chachamim rule that he loses 30 days of his Nezirus. Why, though, should he lose anything at all? He accepted only a 100-day Nezirus, which he observed in full! He merely needs to wait until day 101 to bring his Korbanos, and if he becomes Tamei at that point, he does not become Tamei during the observance of his Nezirus and he should not lose any days. In fact, the Rishonim point out that if he becomes Tamei on day 102 (before he brings his Korbanos), everyone agrees that he does not lose any days because his Nezirus is completed. Why, then, when he becomes Tamei on day 101, should he lose any days? If, for some reason, the Tum'ah on day 101 is "Soser" his Nezirus, why should he lose 30 days?

(a) TOSFOS and the ROSH explain that Rav Masna and Bar Pada understand the Chachamim's reason (for why a Nazir who becomes Tamei on day 30 of a Stam Nezirus loses his Nezirus) in two different ways. According to Rav Masna (who says that Stam Nezirus is 30 days), a Nazir who becomes Tamei loses his Nezirus because he has not yet finished his Nezirus. However, if Rav Masna rules that "Miktzas ha'Yom k'Kulo" and the Nezirus is completed at the beginning of day 30, why has he not finished his Nezirus? Tosfos and the Rosh answer that "Miktzas ha'Yom k'Kulo" applies only when the Nazir actually ends his Nezirus by bringing his Korbanos of Nezirus Taharah. When he does an action to end his Nezirus, he is able to make "Miktzas ha'Yom k'Kulo" take effect. "Miktzas ha'Yom k'Kulo" does not work automatically if he does nothing to end the Nezirus. In the case of the Mishnah, the Nazir does nothing to end the Nezirus. Rather, he becomes Tamei before the end of the day and is unable to bring his Korbanos of Nezirus Taharah. Since he does not actively end the Nezirus, "Miktzas ha'Yom k'Kulo" does not apply and he is no different from a Nazir who became Tamei in the middle of his Nezirus. Therefore, the Chachamim rule that he loses the entire Nezirus. Rebbi Eliezer, who rules that he does not lose the Nezirus, maintains that "Miktzas ha'Yom k'Kulo" applies even when the Nazir does nothing to end the Nezirus. This is how Rav Masna understands the dispute between the Chachamim and Rebbi Eliezer.

According to Bar Pada (who says that Stam Nezirus is 29 days), the Gemara concludes that the Nazir loses 30 days because of a Gezeirah d'Rabanan, as the Gemara earlier (5b) says. This Gezeirah -- that the Nazir loses all of his Nezirus if he becomes Tamei on day 30 -- was instituted because of a case in which the Nazir explicitly accepts upon himself to observe Nezirus for 30 days (in which case he must observe 30 complete days). People are accustomed to observing Nezirus for 30 days since they cannot bring their Korbanos until day 30, and thus they think that Stam Nezirus is 30 days. When one says that he will observe Nezirus for 30 days, according to Bar Pada he must observe 30 complete days of Nezirus and bring the Korbanos on day 31 (since Bar Pada does not agree that "Miktzas ha'Yom k'Kulo"). The Rabanan therefore decreed that in every case of a Stam Nezirus the Nazir should bring the Korbanos on day 31 and count day 30 as part of his Nezirus lest people confuse Stam Nezirus with a Nazir who explicitly accepted to observe 30 days of Nezirus.

This approach explains why the Chachamim rule that a Nazir loses the entire Nezirus when he becomes Tamei on day 30 of a Stam Nezirus. Why, though, do they rule that a Nazir loses 30 days of a 100-day Nezirus when he becomes Tamei on day 101? Tosfos explains that according to both Rav Masna and Bar Pada, the Nazir loses his 100 days of Nezirus because of a Gezeirah d'Rabanan. The Rabanan decreed that a Nazir who becomes Tamei on day 101 of a 100-day Nezirus loses 30 days lest the case be confused with a Nazir who becomes Tamei on day 30 of a Stam Nezirus, in which case he loses 30 days. According to Rav Masna, the Nazir who becomes Tamei on day 30 loses his 30 days mid'Oraisa, and thus it is appropriate to decree that a 100-day Nazir who becomes Tamei on day 101 loses 30 days of his Nezirus. According to Bar Pada, who maintains that the loss of days of Nezirus due to Tum'ah on day 30 is only mid'Rabanan, it must be that both cases are included in one general Gezeirah -- that when a Nazir becomes Tamei on day 30 or on day 101 he loses 30 days (and it is not considered a Gezeirah l'Gezeirah).

Why, though, is day 101 of a 100-day Nezirus comparable with day 30 of a 30-day Nezirus such that the Rabanan needed to make a Gezeirah on one because of the other? Why will people confuse the two days?

The answer, according to Bar Pada, is simple. Both days (101 and 30) follow a full Nezirus period; they are the days on which a Korban is brought. According to Bar Pada, day 29 of a Stam Nezirus is the last day of a Stam Nezirus and day 30 is the day which follows it. Similarly, day 101 (of a 100-day Nezirus) is the day which follows the completion of the Nezirus (on day 100), and it is the day on which the Korbanos may be brought. The Gezeirah d'Rabanan states that whenever a Nazir becomes Tamei on a day on which the Korbanos may be brought, he loses 30 days. The Gezeirah thus reminds Nezirim who become Tamei on day 30 of a Stam Nezirus to re-observe 30 days of Nezirus (whether or not they explicitly accepted to observe 30 days or merely to observe a Stam Nezirus).

According to Rav Masna, the Nazir who becomes Tamei on day 30 loses 30 days because "Miktzas ha'Yom k'Kulo" does not apply, and it is considered as though he become Tamei in the middle of his Nezirus. Why will people confuse that case with the case of a 100-day Nazir who becomes Tamei on day 101, the day after the Nezirus is finished? What does day 101 of a 100-day Nezirus have in common with day 30 of a 30-day Nezirus? Day 30 is part of the actual Nezirus (since a Stam Nezirus is 30 days), while day 101 is not (the Nezirus is only 100 days)!

The answer is that people do not realize that "Miktzas ha'Yom k'Kulo" does not apply when the Nazir becomes Tamei before he brings his Korbanos. They think that "Miktzas ha'Yom k'Kulo" applies automatically (as Rebbi Eliezer maintains). Consequently, they assume that day 30 is observed as Nezirus simply because the Nazir has not yet brought his Korbanos. They compare it to day 101 of a 100-day Nezirus, which the Nazir also observes merely because he has not yet brought his Korbanos. Accordingly, the Rabanan decreed that the Nazir loses 30 days when he becomes Tamei on day 101 so that people not confuse this case with that of a 30-day Nazir who becomes Tamei on day 30, according to Rav Masna.

(b) The RAMBAM (Perush ha'Mishnayos) takes an entirely different approach to the Mishnah. The Rambam explains that when a Nazir becomes Tamei on day 30, according to Rav Masna "Miktzas ha'Yom" is "k'Kulo" according to everyone; both Rebbi Eliezer and the Chachamim agree that "Miktzas ha'Yom" is "k'Kulo" and that once the day has begun, the Nezirus is completed. Why, then, do the Chachamim rule that he loses 30 days when he becomes Tamei on day 30? The Rambam answers that the Chachamim maintain that whenever a Nazir becomes Tamei on the day on which he brings his Korbanos, he loses 30 days. The Rambam apparently understands that this requirement is a Halachah mid'Oraisa: a Nazir loses 30 days of Nezirus (according to the Chachamim) when he becomes Tamei on the day on which he is supposed to bring his Korbanos and complete his Nezirus. Rebbi Eliezer says that he does not lose any days of the Nezirus, but he simply counts seven days until he becomes Tahor.

The Rambam explains that the Chachamim are consistent with their own view in the case of a Nazir who becomes Tamei on day 101. Like day 30 of a Stam Nezirus, day 101 of a 100-day Nezirus is the day on which a Nazir is supposed to bring his Korbanos. The Chachamim rule that he loses 30 days because they maintain that a Nazir who becomes Tamei on the day on which he is supposed to bring his Korbanos loses 30 days. Rebbi Eliezer also is consistent with his own view and rules that the Nazir loses none of his Nezirus.

This explanation is especially consistent with the words of the Gemara here (beginning of 16b) which explains that Rebbi Eliezer's reason (for why a Nazir who becomes Tamei on day 30 needs to wait only seven days) is that he maintains that becoming Tamei on the day of "Achar Melos" is "Soser" only seven days. According to the way Tosfos learns, the Gemara does not address the main issue. The main point of dispute between Rebbi Eliezer and the Chachamim in the case of a Nazir who becomes Tamei on day 30, according to Rav Masna, is not whether "Achar Melos" is "Soser" seven days; everyone agrees that after the Nezirus is over he loses only seven days! The question is whether this day (day 30) is considered "Achar Melos" because "Miktzas ha'Yom k'Kulo" applies on day 30, or whether it is considered "Toch Melos" (within the Nezirus) because "Miktzas ha'Yom k'Kulo" does not apply when he becomes Tamei.

According to the Rambam, however, the Gemara's words are precise. The Gemara states that according to Rebbi Eliezer "Achar Melos" is "Soser" seven days, which implies that according to the Chachamim "Achar Melos" is always "Soser" 30 days, as the Rambam explains.

However, the words of the Gemara earlier (beginning of 6b) are not consistent with the Rambam's explanation. The Gemara there adduces proof for the view of Rav Masna from the Mishnah here. Apparently, the Rambam's Girsa of the text of the Gemara there differs from the Girsa of our texts. His Girsa was consistent with his explanation of the Mishnah here.

According to the Rambam, what is the Chachamim's source that when a Nazir becomes Tamei on the day on which he is supposed to bring Korbanos, he loses 30 days of his Nezirus? The Rambam may understand that the Chachamim agree with Rebbi Eliezer's Derashah of "Ten Lo Toras Melos" which the Gemara earlier (6b) mentions, which teaches that when a Nazir becomes Tamei on "Yom Melos" (the last day of his Nezirus) he loses 30 days. Apparently, the Chachamim agree with this Derashah, according to the Rambam. However, they apply it only to a Nazir who becomes Tamei "Achar Melos," on the day on which he is supposed to bring Korbanos for his Nezirus, but not to a Nazir who becomes Tamei on "Yom Melos," on the last day of his Nezirus.