Mishnah Negaim 10:5: How does one shave the Netek [during the second week of quarantine]? He shaves outside of it and leaves two [normal] hairs adjacent to it, so that it will be recognizable if it expands. If [the priest] decided [the Netek was impure] through yellow hair, [and then] the yellow hair went away and [then] the golden hair returned, and so too with expansion, [whether this happened] initially, at the end of the first week, at the end of the second week, or after the exemption [that made the Netek pure], [the Netek] is like it was [i.e. it is impure]. If [the priest] decided [the Netek was impure] through expansion, [and then] the expansion went away and [then] the expansion returned, so too with yellow hair, [whether this happened] at the end of the first week, at the end of the second week, or after the exemption [that made the Netek pure], [the Netek] is like it was [i.e. it is impure].

כֵּיצַד מְגַלְּחִין אֶת הַנֶּתֶק. מְגַלֵּחַ חוּצָה לוֹ וּמַנִּיחַ שְׁתֵּי שְׂעָרוֹת סָמוּךְ לוֹ, כְּדֵי שֶׁיְּהֵא נִכָּר אִם פָּשָׂה. הֶחְלִיטוֹ בְשֵׂעָר צָהֹב, הָלַךְ שֵׂעָר צָהֹב וְחָזַר שֵׂעָר צָהֹב, וְכֵן בְּפִשְׂיוֹן, בַּתְּחִלָּה, בְּסוֹף שָׁבוּעַ רִאשׁוֹן, בְּסוֹף שָׁבוּעַ שֵׁנִי, לְאַחַר הַפְּטוּר, הֲרֵי הוּא כְמוֹת שֶׁהָיָה. הֶחְלִיטוֹ בְּפִשְׂיוֹן, וְהָלַךְ הַפִּשְׂיוֹן וְחָזַר הַפִּשְׂיוֹן. וְכֵן בְּשֵׂעָר צָהֹב, בְּסוֹף שָׁבוּעַ רִאשׁוֹן, בְּסוֹף שָׁבוּעַ שֵׁנִי, לְאַחַר הַפְּטוּר, הֲרֵי הוּא כְמוֹ שֶׁהָיָה:

Mishnah Negaim 10:6: Two Netakim, one beside the other, and a row of [normal] hair separates between them, [if the row] is broken in one place, he is impure. In two places, he is [still] pure. How [wide] is a breakage? The area of two hairs. [If] it was broken in one place [even the size of] a bean, he is impure.

שְׁנֵי נְתָקִים, זֶה בְצַד זֶה, וְשִׁיטָה שֶׁל שֵׂעָר מַפְסֶקֶת בֵּינֵיהֶם, נִפְרַץ מִמָּקוֹם אֶחָד, טָמֵא. מִשְּׁנֵי מְקוֹמוֹת, טָהוֹר. כַּמָּה תְהֵא הַפִּרְצָה, מְקוֹם שְׁתֵּי שְׂעָרוֹת. נִפְרַץ מִמָּקוֹם אֶחָד כַּגְּרִיס, טָמֵא: