Nazir Chapter 6, Mishnah 7. In the previous Mishnah we dealt with the shaving of tumah - the process by which a nazir becomes pure again after he has become tamei. Our Mishnah comes to teach the law of the shaving of purity: how a nazir completes his nezirus when he remained pure throughout his days and never became tamei. This conclusion too involves a shaving, the shaving of the head.
The Three Offerings:
The nazir brings three animals, three different offerings:
Chatas - a female lamb in its first year.
Olah - a male lamb within its first year.
Shelamim - a ram, for the peace offering.
Which Offering Does He Shave Over?
"V'shochet es hashelamim umegaleiach aleihem, divrei Rabbi Yehudah" - in the opinion of Rabbi Yehudah, after the slaughtering of the shelamim the nazir performs the shaving.
"Rabbi Elazar omer: lo yegaleiach ela al hachatas" - Rabbi Elazar disagrees and holds that the shaving is done over the chatas offering, after it has been slaughtered, "shechatas kodemes b'chol makom" - because the chatas always takes precedence, and it is the offering over which he shaves.
"V'im gilach al echad mishelashtan - yatza" - after the fact, if he shaved his head after bringing any one of the three offerings, he has fulfilled the obligation of shaving according to all opinions. Even though one opinion holds that the shaving is over the shelamim and the other holds that it is over the chatas, after the fact any one of the offerings suffices, and once he has brought one of them his shaving is valid.
In summary: in this Mishnah we learned the order of the shaving of purity: the nazir brings three offerings - a chatas, an olah and a shelamim; in the opinion of Rabbi Yehudah he shaves over the shelamim, and in the opinion of Rabbi Elazar over the chatas, since the chatas always takes precedence. And after the fact, if he shaved over any one of the three offerings, he has fulfilled his obligation.