Parashas Naso
וְהִקְרִ֣יב אֶת־קׇרְבָּנ֣וֹ לַיהֹוָ֡ה כֶּ֩בֶשׂ֩ בֶּן־שְׁנָת֨וֹ תָמִ֤ים אֶחָד֙ לְעֹלָ֔ה וְכַבְשָׂ֨ה אַחַ֧ת בַּת־שְׁנָתָ֛הּ תְּמִימָ֖ה לְחַטָּ֑את וְאַֽיִל־אֶחָ֥ד תָּמִ֖ים לִשְׁלָמִֽים׃
As an offering to GOD they shall present: one male lamb in its first year, without blemish, for a burnt offering; one ewe lamb in its first year, without blemish, for a purgation offering; one ram without blemish for an offering of well-being;
Torah Temimah points to TT / Nazir (verified).
לחטאת ואיל אחד — הקיש איל לחטאת: שאם גלח על אחד משלשתן יצא.
English: “For a sin-offering and one ram” — Scripture compares the ram to the sin-offering: if he shaved after any one of the three offerings, he has fulfilled [the requirement].
Custom
Chazal teach that shaving after any one of the three concluding offerings discharges the nazir’s hair obligation.