Jerusalem Talmud Nazir 2:6

משנה: הֲרֵי עָלַי לְגַלַּח חֲצִי נָזִיר וְשָׁמַע חֲבֵירוֹ וְאָמַר וַאֲנִי עָלַי לְגַלַּח חֲצִי נָזִיר זֶה מְגַלֵּחַ נָזִיר שָׁלֵם וְזֶה מֶגַלֵּחַ נָזִיר שָׁלֵם דִּבְרֵי רִבִּי מֵאִיר. וַחֲכָמִים אוֹמְרִים זֶה מְגַלֵּחַ חֲצִי נָזִיר וְזֶה מְגַלֵּחַ חֲצִי נָזִיר. MISHNAH: “I am taking upon myself to shave half a nazir,” and his neighbor heard it and said, “I also am taking upon myself to shave half a nazir,” each one of them shaves an entire nazir, the words of Rebbi Meïr⁹⁰Since the sacrifice of a nazir must either be brought whole or not at all; the vow for half the sacrifices (which would be 1½ animals) is impossible. Since he made the vow, it has to be interpreted as a vow for a whole set of animals.. But the Sages say, each of them shaves half a nazir⁹¹The vow simply was for paying half the expenses of one nazir..

הלכה: הֲרֵי עָלַי לְגַלַּח חֲצִי נָזִיר כול׳. רִבִּי אַבָּהוּ בְשֵׁם רִבִּי יוֹחָנָן וְרַב חִסְדָּא תְּרַוֵּיהוֹן אָֽמְרִין. בִּסְתָם חֲלוּקִין. מַה מְקַייְמִין. אִם בְּאוֹמֵר. כָּל־חֲצִי רֹאשׁ. כָּל־עַמָּא מוֹדוֹי שֶׁהוּא מְגַלֵּחַ נָזִיר שָׁלַם. אִם בְּאוֹמֵר. חֲצִי חוֹבָה. כָּל־עַמָּא מוֹדֵיי שֶׁהוּא מְגַלֵּחַ חֲצִי נָזִיר. אָלָּא כֵּן אֲנָן קַייְמִין בְּאוֹמֵר. חֲצִי. רִבִּי מֵאִיר אוֹמֵר בְּאוֹמֵר. חֲצִי רֹאשׁ. וְרַבָּנִין אָֽמְרִין. בָּאוֹמֵר חֲצִי חוֹבָה. אָמַר רִבִּי יוּדָן. אַשְׁכַּח אָמַר קַלָּת וְחוּמְרָת. עַל דַּעְתֵּיהּ דְּרִבִּי מֵאִיר דּוּ אָמַר. חֲצִי רֹאשׁ. מֵבִיא קָרְבָּן אֶחָד. שֶׁכֵּן הַנָּזִיר מְגַלֵּחַ עָלָיו קָרְבָּן שָׁלֵם. עַל דַּעְתּוֹן דְּרַבָּנִין דְּאִינּוּן אָֽמְרִין. חֲצִי חוֹבָה. מֵבִיא קָרְבָּן וּמֶחֱצָה חֲצִי חוֹבַת יָחִיד. HALAKHAH: “I am taking upon myself to shave half a nazir,” etc. Rebbi Abbahu in the name of Rebbi Joḥanan and Rav Ḥisda both say that they disagree if it was not spelled out. What are we dealing with? If he said, every half head⁹²If he vows half of every animal, he has to give three animals since half an animal is no sacrifice., everybody agrees that he completely shaves a nazir. If he says, half of the obligation, everybody agrees that he shaves half a nazir. But we are dealing with the case that he says: “half”. Rebbi Meïr says, as if he said half a head, but the rabbis said, as if he said, half of the obligation. Rebbi Yudan said, it turns our that leniency is a restriction. In the opinion of Rebbi Meïr who said, as if he had said half a head, he brings one sacrifice since the nazir can shave on one sacrifice⁹³. Nazir 6:5:1" href="/Jerusalem_Talmud_Nazir.6.5.1">Mishnah 6:7 states that a nazir can shave even if he brings only one sacrifice. (Note that the vow is interpreted as meaning “half a head”, not “every half head”).. In the opinion of the rabbis who said, half of the obligation, he has to pay for a sacrifice and a half, half of the obligation of a person.