Answer #1: Really, he said "I will be a Nazir today. I will be a Nazir tomorrow." What he observed fulfills the second Nezirus, except for the last day.

Answer #2: He accepted both simultaneously. (There is no reason to say that one takes effect more than the other.)

Question (Rav Hamnuna - Beraisa): "Nazir Lehazir" teaches that Nezirus takes effect on Nezirus;

A Kal v'Chomer suggests that it should not! Shevuos are more stringent, yet a Shevu'ah does not take effect on a Shevu'ah. Nezirus is more lenient, all the more so, Nezirus should not take effect on Nezirus! Therefore, the verse is needed.

Question: What is the case?

If he said "I will be a Nazir today. I will be a Nazir tomorrow", we wouldn't need a verse to teach us that both take effect!

Answer: We must say that he said "I will be a Nazir today. I will be a Nazir today", and both take effect!

Answer: The case is, he accepted them simultaneously.

Question: Why did the Tana say that Shevuos are more stringent than (Nezirus, i.e.) Nedarim?

Suggestion: A Shevu'ah takes effect even on something intangible.

Rejection: There is also a stringency of Nedarim, i.e. they take effect even on Mitzvos!

Answer: It says "Lo Yenakeh (Hash-m will not cleanse one who swore falsely.)"

(Mishnah): If he said "Shevu'ah, I will not eat this. Shevu'ah, I will not eat this" and he ate it, he is liable only once.

Version #1 (Rava): If he permitted the first oath, the second takes effect.

He derived this from the Mishnah. "He is liable only once" connotes that there is no room for the second oath to take effect, but when he permits the first (and there is room), it takes effect.

Version #2 - Inference: He is not liable for the second, but it is a Shevu'ah.

Question: In what sense is it a Shevu'ah?

Answer: This is like Rava taught, that if he permits the first, the second takes effect. (end of Version #2. Pores Yosef - according to Version #1, he cannot permit the second Shevu'ah before the first, for it merely a potential Shevu'ah.)

Support (Beraisa): If one accepted two terms of Nezirus, observed one, was Makdish a Korban for it, and then permitted his first Nezirus, what he observed counts for the second.

Rejection: Perhaps he accepted both terms at once.

(Mishnah - R. Meir): We are stringent about a Stam (unspecified) Neder. If he explained it, we are lenient;

If a person forbade something "like salted meat" or "like Yayin Nesech (libations of wine)":

If he (says that he) referred to a Shelamim (some texts - of Shamayim), he is forbidden. If he referred to idolatry, he is permitted. (Idolatry is Davar ha'Asur, not Devar ha'Nadur.) If he vowed Stam, he is forbidden.

If he said 'this is like Cherem to me":

If he referred to Cherem of Shamayim (Hekdesh Bedek ha'Bayis), he is forbidden. If he referred to Cherem that is given to Kohanim, he is permitted. (Presumably, he refers to after the Kohen gets it. It is permitted then.) If he vowed Stam, he is forbidden.

If he said "this is like Ma'aser to me":

If he referred to Ma'aser Beheimah, he is forbidden. If he referred to Ma'aser of produce, he is permitted. If he vowed Stam, he is forbidden.

If he said "this is like Terumah to me":

If he referred to Terumas ha'Lishkah (Shekalim taken to buy Korbanos), he is forbidden. If he referred to Terumah of produce, he is permitted. If he did not specify, he is forbidden.

R. Yehudah says, in Yehudah, if he said Terumah Stam, he is forbidden. In Galil, he is permitted, for there (they are far from Yerushalayim, so) people are not familiar with (and do not regularly discuss) Terumas ha'Lishkah;

If he said Cherem Stam, in Yehudah he is permitted. In Galil he is forbidden, for people there are not familiar with Cherem of Kohanim.

(Gemara) Contradiction (Mishnah #1): We are lenient about Safek Nezirus. (Our Mishnah is stringent about Safek Nedarim!)

Answer #1 (R. Zeira): Mishnah #1 is like R. Eliezer Our Mishnah is like Chachamim:

(Beraisa): If one was Makdish his Chayah or his Beheimah (his wild or domestic animal; Rashi - he was Makdish both of them), his Koy (a Safek Chayah, Safek Beheimah) becomes Kodesh.

R. Eliezer says, it is not Kodesh.

Chachamim say that a person forbids his property due to a Safek, and similarly regarding (forbidding) himself;

R. Eliezer holds that one does not forbid his property due to a Safek, and all the more so regarding himself.