SB 11.23.5

kenacid bhikṣuṇā gītaṁ
 paribhūtena durjanaiḥ
smaratā dhṛti-yuktena
 vipākaṁ nija-karmaṇām
Word for word: 
kenacit — by a certain; bhikṣuṇā — sannyāsī; gītam — sung; paribhūtena — who was insulted; durjanaiḥ — by impious persons; smaratā — remembering; dhṛti-yuktena — fixing his resolution; vipākam — the consequences; nija-karmaṇām — of his own past activities.
Translation: 
Once a certain sannyāsī was insulted in many ways by impious men. However, with determination he remembered that he was suffering the fruit of his own previous karma. I will narrate to you his story and that which he spoke.
Purport: 

Śrīla Bhaktisiddhānta Sarasvatī Ṭhākura comments as follows. “Often those who give up the materialistic path and devote themselves to renunciation are attacked by impious persons. This analysis, however, is superficial, since the punishment is actually the cumulative result of one’s past karma. Some renunciants show lack of tolerance when presented with the remnants of their previous sins and thus are forced to enter again onto the path of impious life. Śrī Caitanya Mahāprabhu therefore instructs that one should become as tolerant as a tree. If a neophyte on the path of devotional service to the Lord’s pure devotees is attacked by envious persons, he must accept it as a consequence of his previous fruitive activities. One should be intelligent and avoid future unhappiness by rejecting the ethic of an eye for an eye, a tooth for a tooth. If one refuses to enter into enmity with envious men, they will automatically leave him alone.”