Berakhot 48A

לאתויי קטן פורח?

to include a mature minor? Explain the baraita as follows: A minor who grew two hairs is included in a zimmun, and we are not exacting with regard to a minor to ascertain whether or not he has reached the age of majority.

ולית הלכתא ככל הני שמעתתא, אלא כי הא דאמר רב נחמן: קטן היודע למי מברכין ⁠— מזמנין עליו.

The Talmud concludes: The halakha is not in accordance with all of these statements. Rather, the halakha is in accordance with this statement that Rav Naḥman said: A minor who knows to Whom one recites a blessing is included in a zimmun.

אביי ורבא הוו יתבי קמיה דרבה. אמר להו רבה: למי מברכין? אמרי ליה: לרחמנא. ורחמנא היכא יתיב? רבא אחוי לשמי טללא. אביי נפק לברא, אחוי כלפי שמיא. אמר להו רבה: תרוייכו רבנן הויתו. היינו דאמרי אינשי: בוצין בוצין מקטפיה ידיע.

The Talmud relates that Abaye and Rava, when they were children, were seated before Rabba. Rabba said to them: To whom does one recite blessings? They said to him: To God, the All-Merciful. Rabba asked them: And where does the All-Merciful reside? Rava pointed to the ceiling. Abaye went outside and pointed toward the heaven. Rabba said to them: You will both become rabbis. It is as the popular saying goes: A cucumber can be recognized from its blossoming stage. Similarly, a great person can be recognized even from a young age.

אמר רב יהודה בריה דרב שמואל בר שילת משמיה דרב: תשעה אכלו דגן ואחד אכל ירק ⁠— מצטרפין. אמר רבי זירא: בעאי מיניה מרב יהודה: שמנה מהו? שבעה מהו? אמר לי: לא שנא. ששה ודאי לא מבעיא לי. אמר ליה רבי ירמיה: שפיר עבדת דלא איבעיא לך, התם טעמא מאי ⁠— משום דאיכא רובא, הכא נמי איכא רובא. ואיהו סבר רובא דמינכר בעינן.

Rav Yehuda, son of Rav Shmuel bar Sheilat, said in the name of Rav: If 9 ate grain and one ate vegetables, they join and form a zimmun of 10. R' Zeira said: I raised a dilemma before Rav Yehuda: What is the ruling if 8 ate grain and two ate vegetables? May they join together? What is the ruling if 7 ate grain? He said to me: There is no difference. I certainly had no dilemma with regard to 6, as it was clear to me that 6 are insufficient to warrant a zimmun. R' Yirmeya said to him: You did well that you had no dilemma with regard to 6, but for the opposite reason. There, in the case of 7 or 8, what is the reason that they form a zimmun of 10? Because there is a majority of those dining who ate grain. Here, too, there is a majority. R' Zeira, however, held: We require an obvious majority. Therefore, contrary to the opinion of R' Yirmeya, it was clear to him that 6 who ate grain are insufficient to form a zimmun.