SB 10.64.41

vipraṁ kṛtāgasam api
 naiva druhyata māmakāḥ
ghnantaṁ bahu śapantaṁ vā
 namas-kuruta nityaśaḥ
Word for word: 
vipram — a learned brāhmaṇa; kṛta — having committed; āgasam — sin; api — even; na — not; eva — indeed; druhyata — do not treat inimically; māmakāḥ — O My followers; ghnantam — striking physically; bahu — repeatedly; śapantam — cursing; — or; namaḥ-kuruta — you should offer obeisances; nityaśaḥ — always.
My dear followers, never treat a learned brāhmaṇa harshly, even if he has sinned. Even if he attacks you physically or repeatedly curses you, always continue to offer him obeisances.

Lord Kṛṣṇa offers this instruction not only to His personal associates but to all those who claim to be followers of the Supreme Personality of Godhead.