כָּל־יְמֵי֙ נֶ֣דֶר נִזְר֔וֹ תַּ֖עַר לֹא־יַעֲבֹ֣ר עַל־רֹאשׁ֑וֹ עַד־מְלֹ֨את הַיָּמִ֜ם אֲשֶׁר־יַזִּ֤יר לַיהוָה֙ קָדֹ֣שׁ יִהְיֶ֔ה גַּדֵּ֥ל פֶּ֖רַע שְׂעַ֥ר רֹאשֽׁוֹ׃
Во все дни его клятвы назорейства не должно быть бритвы на его голову; пока не исполнятся дни, в которые он посвятит себя Господу, он будет свят, и пусть прядь волос на голове его будет расти долго.
Sefer HaChinukh
That the nazirite not shave his hair: That the nazirite not shave his hair, all of the days of his naziriteness, as it is stated (Numbers 6:5) "a razor shall not pass over his head."
Sefer HaChinukh
The commandment of growing the hair of the nazirite: That the nazirite - who is the person who separated himself from wine - is commanded to let his head hair grow for all the days of his naziriteness for God, as it states (Numbers 6:5), "he shall grow the locks of his head." And the language of Mekhilta (Sifra Zuta on Numbers 6:5) is "'He shall grow the hair' is a positive commandment. From where [do I know there is also a] negative commandment? Hence, it teaches to say 'a blade shall not pass over his head.'"