śatror api guṇā grāhyā doṣā vācyā guror api
śatror api guṇā grāhyā doṣā vācyā guror api |
sarvathā sarva-yatnena putre śiṣye hitaṁ vadet ||
(Mahābhārata: 4.51.15)
“Qualities even of an enemy are to be accepted, and faults even of an elder (guru) are to be acknowledged. With all [due] care one should under all circumstances say that which is beneficial for a son and a disciple.”