רמב"ן — וביום מלאת ימי נזרו / וכבשה אחת בת שנתה לחטאת

Q — When the nazir completes his vow, he brings a chatat among his korbanot. What sin did he commit by completing his nezirut? Chazal (R' Elazar HaKappar): he sinned by depriving himself of wine in the first place. But this assumes nezirut is a sin — and R' Elazar holds the opposite, that the nazir is kadosh.

A — Ramban (following the kadosh view): the chatat doesn't atone for the past abstention but for the *decision to end the nezirut*. As nazir he stood comparable to a navi — 'ואקים מבניכם לנביאים ומבחוריכם לנזירים' — and 'ראוי היה לו שיזיר לעולם.' Returning to the appetites of ordinary life is a spiritual regression, captured beautifully in the wordplay: the נזיר becomes נזור — separated, then receded — 'נזור מקדושתו.' The chatat is brought 'בשובו להטמא בתאוות העולם.' (Rabbeinu Bachya marvels that this would be a chatat brought on a future decision — but, as Ramban implies, it's a chatat for the present decision to descend.)