״הִרְתִּיעַ לַאֲחוֹרָיו אֵינוֹ נָזִיר״ כו'. טַעֲמָא – מִשּׁוּם דְּהִרְתִּיעַ לַאֲחוֹרָיו, הָא אָתֵי לְקַמָּן – הָוֵי נָזִיר. מַנִּי?

§ The mishna taught that if the individual walking toward them turned back, so that his identity remained unknown, not one of them is a nazirite. The Gemara clarifies: The reason is only because he turned back, from which it may be inferred that if that person comes before us and is identified, the one who said he would be a nazirite if it is so-and-so is considered to be a nazirite. The Gemara inquires: In accordance with whose opinion is this halakha ?