na tena vṛddho bhavati yenāsya palitaṁ śiraḥ
na tena vṛddho bhavati yenāsya palitaṁ śiraḥ |
yo vai yuvāpy adhīyānaḥ taṁ devās sthaviram viduḥ ||
(Manu-smṛti: 2.156)
“One does not become wise [i.e., venerable, lit., ‘an elder’] just because one has grey hair on one’s head. The devas recognize as an elder one who, although young, remains engaged in studying.”