Manava Dharmashastra 2.154

2.154

iyamaparā'dhyāpakapraśaṃsā | hāyanaśabdaḥ saṃvatsaraparyāyaḥ| na bahubhirvarṣaiḥ pariṇatavayā mahānpūjyo bhavati, na palitaiḥ keśaśmaśruromabhiḥ śuklainai vittena bahunā, na bandhubhiḥ | prāguktāni mānyasthānānyāpadyante | samuditairna mahānbhavati, kiṃ tarhi ekayaiva vidyayā | yasmādṛṣayaścakrire | ṛṣirdarśanāt | niḥśeṣavedārthadarśino niścityaṃmaṃ dharmaṃ vyavasthāpitavantaḥ | yo'nūcānaḥ, anuvacanamadhyāpanaṃ kṛtsāṅgasya vedasya, sa no'smākaṃ mahānchreṣṭhaḥ | karotirvyavasthāpane vartate, nābhūtajanane |

Neither by years, nor by grey hair, nor by wealth, nor by relatives (is greatness attained); since the sages have made the law that ‘he who teaches is the greatest among us.’—(154)

Medhātithi’s commentary (manubhāṣya):
This is another eulogy of the teacher.

‘Hāyana’ is synonymous with ‘samvatsara,’ ‘years.’ One does not become great—venerable—by being advanced in age by many years;—‘nor by grey hair’—i.e., by the hairs of the head and beard becoming white;—‘nor by (much) wealth’;—‘nor by relatives,’—does one acquire the aforesaid title to respect. One does not become ‘great’ even by all these taken together; but by learning alone. And this because ‘the sages have made the law,’—‘Ṛṣi,’ ‘sage,’ is so called by reason of his sublime vision. The meaning is that the ‘seers’ of the text and meaning of the entire Veda, have come to the conclusion and laid down this law—‘he who teaches’—‘teaching’ means instructing in the Veda along with all its subsidiaries—‘is the greatest’—most venerable—‘among us.’

The term ‘made’ stands for laying not for bringing into existence what did not exist before.—(154)

‘Anūcānaḥ’—‘Teacher of the Veda’ (Medhātithi and Govindarāja);—‘he who has learnt the Veda’ (Kullūka, Nārāyaṇa, Nandana and Rāghavānanda).

This verse is quoted in Parāśaramādhava (Ācāra, p. 305);—in Vīramitrodaya (Saṃskāra p. 480);—and in Smṛticandrikā (Saṃskāra, p. 93), which explains the meaning as, ‘the sages have not laid down the principle that greatness depends on years and the rest; what they have asserted is that among us he is great who is the best expounder of the ‘Veda.’

“This verse with the following one is proverbial, and is repeated several times in the Mahābhārata and the other law-books.”—Hopkins.

Comparative notes by various authors
(verse 150-154)
See Comparative notes for Verse 2.150.