(Mishnah): [If one said] 'I am a Nazir, and I will be a Nazir when I have a son', and he started his Nezirus, and a son was born to him, he finishes his Nezirus, then counts [the Nezirus that he accepted for birth] of his son.

If he said 'I will be a Nazir when I have a son, and I am a Nazir', and he began his Nezirus, and a son was born to him, he interrupts his Nezirus, counts [the Nezirus] of his son, then completes his Nezirus.

(Gemara - R. Yosi) Question: [If one said] 'I am a Nazir these 30 days, and [I accept another Nezirus in] these [same] 30 days' [what is the law]? (Do we say that he is already a Nazir, and Ein Isur Chal Al Isur?)

Answer (R. Ze'ira, in front of R. Mana): Does our Mishnah (the Seifa) not teach this? He interrupts his Nezirus, counts [the Nezirus] of his son, then completes his Nezirus. [Is this not] even if his wife is on the birthing stool (she will give birth today, so he accepts two Neziriyos starting today)?!

Rebuttal (R. Mana): His Nezirus is unlike Nezirus Beno. (It is not certain that the birth will be today. We explained this like OHR YAKOV. Alternatively, perhaps it is not certain that a son will be born. However, if he accepted Nezirus when a child will be born, we can learn from our Mishnah. Nefalim are a small minority; it is as if he Vadai accepted two Neziriyos starting today. - PF)

Retraction: Rather, [we can learn from our Mishnah if one said] 'I am a Nazir now, and a Nazir after 20 days.' (The Reisha says that even for Nezirus Beno, he finishes his Nezirus, and then counts Nezirus Beno. All the more so he does not interrupt for Stam Nezirus!)

(R. Lazar and R. Yosi bar Chanina): If he finished his Nezirus [before the birth of the son], Nezirus Beno does not take effect on him until he brings Korban [Nazir] and shaves. This refers only to a Nazir who became Tamei.

Question: R. Yosi ben Chaninah contradicts himself! There, he says that if a Tamei Mes accepted Nezirus, his seventh day [on which he becomes Tahor] counts towards the number [of days he must observe Nezirus]. If a Nazir became Tamei, his seventh day does not count towards the number;

And here (after he finishes his Nezirus, he begins Nezirus Beno), is this not like a Tamei Mes who accepted Nezirus? (Since he did not yet start the Nezirus he is about to count, his seventh day should count!)

Answer: No (they are different). A Tamei Mes who accepted Nezirus, his seventh day counts, because he need not bring Korban Tum'ah. This is unlike a Nazir who became Tamei. His seventh day does not count, for he must bring Korban Tum'ah;

And here, since he must bring Korban Tum'ah, his seventh day does not count towards the number. (We explained this like OHR YAKOV.)

(Shimon bar Aba citing R. Yochanan): If he became Tamei during Nezirus Beno, and they warned him due to his Nezirus, he is lashed (it is considered like one long Nezirus).

If he separated his Korbanos [for his Nezirus while conducting Nezirus Beno], they became Kadosh. We are not concerned for R. Chiyah's teaching "Korbano la'Shem Al Nizro" - his Nezirus must precede his Korban, and not that his Korban preceded his Nezirus (for it is like one long Nezirus. SEFER NIR - even though he will need to count 30 new days for his Nezirus after Nezirus Beno, so the first 20 days do not count, they are considered amidst his Nezirus.)

Question (R. Yehudah, to R. Yosi): His Nezirus should precede Nezirus Beno! Didn't R. Avahu say in the name of R. Yochanan, if one said 'this is an Olah after 30 days', and he sold it within 30 days, it is sold. If he was Makdish it [within 30 days, to be a different Korban], it is Kadosh!

Answer (R. Yosi): [R. Yochanan] said so only about one who says 'this [is an Olah].' Did he say so about one who said 'Harei Alai [Olah'?! He did not, for then he has Achrayus to bring an Olah.] One who says 'Harei Ani Nazir', he is like one who says Harei Alai.

(R. Chiyah - Beraisa): [If one accepted Nezirus] 'after 30 days, and [I am] a Nazir from now for 100 days, he counts 20 days and interrupts. He returns to count 30 days (for the first Nezirus he accepted) and returns to count 80 days to complete the first Nezirus [that he started to observe].