עִיקְבֵי נִימְהוֹן שְׁמַע מִינַּהּ מִלְּתַחַת רָבֵי שְׁמַע מִינַּהּ at the roots of their hair. You can learn from it that hair grows from the bottom, as the new hair is not dyed. The Gemara concludes: Indeed, learn from it that it is so.
וְאֶלָּא הָא דְּתַנְיָא נָזִיר שֶׁגִּילְּחוּהוּ לִסְטִים וְשִׁיְּירוּ בּוֹ כְּדֵי לָכוֹף רֹאשׁוֹ לְעִיקָּרוֹ אֵינוֹ סוֹתֵר וְאִי סָלְקָא דַעְתָּךְ מִלְּתַחַת רָבֵי לִיסְתּוֹר כְּגוֹן שֶׁגִּילְּחוּהוּ אַחַר מְלֹאת וּמַנִּי רַבִּי אֱלִיעֶזֶר הִיא דְּאָמַר כׇּל אַחַר מְלֹאת שִׁבְעָה סוֹתֵר The Gemara asks: But what about this halakha that is taught in a baraita: With regard to a nazirite who was shaved by bandits, and they left him with enough hair to bend its end to its root, this does not negate the days of his naziriteship. And if it should enter your mind that hair grows from the bottom, let it negate the days of his naziriteship in that case as well, as the remaining hair grew only after his acceptance of naziriteship. The Gemara answers: This is referring to a case where they shaved him after the completion of his naziriteship but before he sacrificed his offerings, and whose opinion is expressed in this baraita? It is the opinion of Rabbi Eliezer, who says: With regard to any nazirite who became ritually impure after the completion of his term, this negates only seven days.
מַאי טַעְמָא דְּרַבִּי אֱלִיעֶזֶר יָלֵיף תִּגְלַחַת טׇהֳרָה מִתִּגְלַחַת טוּמְאָה מַה תִּגְלַחַת טוּמְאָה שִׁבְעָה אַף תִּגְלַחַת טׇהֳרָה שִׁבְעָה The Gemara asks: What is the reason of Rabbi Eliezer? The Gemara answers: He derives the halakha of the shaving of ritual purity at the end of his term of naziriteship (see Numbers 6:18) from the shaving of impurity (see Numbers 6:9): Just as with the shaving of impurity, if he became impure on the day of the completion of his term he must wait seven days, at which point he is purified from the impurity imparted by a corpse and shaves his hair, so too with the shaving of purity; if he was shaved before he brought his offerings, he negates only seven days.
וְקִים לְהוּ לְרַבָּנַן כׇּל שִׁבְעָה יוֹמִין אָתְיָא מַזְיָיא כְּדֵי לָכוֹף רֹאשׁוֹ לְעִיקָּרוֹ: And the Sages, including Rabbi Eliezer, have an accepted tradition that every seven days hair grows enough to bend its end to its root. Consequently, if this amount of hair remained after he was shaved on the day of the completion of his naziriteship, he does not forfeit any days and need not wait any longer.
נָזִיר שֶׁגִּילַּח בֵּין בְּתַעַר בֵּין בְּזוּג אוֹ שֶׁסִּיפְסֵף כׇּל שֶׁהוּא חַיָּיב תָּנוּ רַבָּנַן תַּעַר אֵין לִי אֶלָּא תַּעַר תָּלַשׁ מֵירַט סִיפְסֵף כׇּל שֶׁהוּא מִנַּיִן תַּלְמוּד לוֹמַר קָדוֹשׁ יִהְיֶה גַּדֵּל פֶּרַע שְׂעַר רֹאשׁוֹ דִּבְרֵי רַבִּי יֹאשִׁיָּה § The mishna taught: With regard to a nazirite who shaved his hair, whether he did so with scissors or with a razor, or if he pulled out any amount, he is liable. The Sages taught: The Torah states with regard to a nazirite: “A razor shall not come upon his head” (Numbers 6:5). I have derived only a razor; from where do I derive that he is liable if he tore out, uprooted, or pulled out any amount of his hair? The verse states: “He shall be holy, he shall let the locks of the hair of his head grow long” (Numbers 6:5). This is the statement of Rabbi Yoshiya.
רַבִּי יוֹנָתָן אוֹמֵר תַּעַר אֵין לִי אֶלָּא תַּעַר מֵירַט תָּלַשׁ סִיפְסֵף כׇּל שֶׁהוּא פָּטוּר וְהָכְתִיב קָדוֹשׁ יִהְיֶה מֵימְרָא דְּאִם גִּילַּח לֵיהּ בְּתַעַר קָאֵים עֲלֵיהּ בַּעֲשֵׂה וְלֹא תַעֲשֶׂה Rabbi Yonatan says a different interpretation: From “razor” I have derived only a razor, whereas if he tore out, uprooted, or pulled out any amount of his hair, he is exempt. The Gemara asks: But isn’t it written: “He shall be holy”? The Gemara answers: That is to say that if he shaved his hair with a razor he stands liable for violating both a positive mitzva and a prohibition. By shaving with a razor he also transgresses the positive mitzva of: “He shall be holy, he shall let the locks of the hair of his head grow long” (Numbers 6:5).
תַּנְיָא אִידַּךְ תַּעַר אֵין לִי אֶלָּא תַּעַר תָּלַשׁ מֵירַט סִיפְסֵף כׇּל שֶׁהוּא מִנַּיִן תַּלְמוּד לוֹמַר לֹא יַעֲבוֹר עַל רֹאשׁוֹ וּמֵאַחַר שֶׁסּוֹפֵינוּ לְרַבּוֹת כֹּל דָּבָר מָה תַּלְמוּד לוֹמַר תַּעַר לֹא יַעֲבוֹר עַל רֹאשׁוֹ It is taught in another baraita: From “razor” I have derived only a razor; from where do I derive that he is also liable if he tore out, uprooted, or pulled out any amount of it? The verse states: “A razor shall not come upon his head” (Numbers 6:5), indicating that he may not remove his hair in any manner. The baraita asks: And since we eventually include everything that removes hair, what is the meaning when the verse states: “A razor shall not come upon his head”? Why does the verse mention a razor, when other implements are equally forbidden?
לְפִי שֶׁלֹּא לָמַדְנוּ לְתִגְלַחַת הָאַחֲרוֹנָה שֶׁיִּהְיֶה בְּתַעַר לְלַמְּדוֹ מִמְּצוֹרָע אִי אֶפְשָׁר The baraita answers: It is because we have not learned that the last shaving, i.e., the nazirite’s shaving of ritual purity, must be performed specifically with a razor, as the verse merely states: “He shall shave his head” (Numbers 6:18), without specifying an implement. It is impossible to learn this requirement from the halakha that a leper must use a razor (see Leviticus 14:9),