Verse 13

उद्दालको नाम मुनिर्मौनी मानी महामतिः ।अप्राप्तयौवनः पूर्वमुवासोद्दामतापसः

In plain words

there once dwelt a sage named Uddālaka — silent, proud of spirit, of great intellect, one of unbridled austerity, who had not yet reached his youth.