SB 6.1.21

kānyakubje dvijaḥ kaścid
 dāsī-patir ajāmilaḥ
nāmnā naṣṭa-sadācāro
 dāsyāḥ saṁsarga-dūṣitaḥ
Word for word: 
kānya-kubje — in the city of Kānyakubja (Kanauj, a town near Kanpur); dvijaḥ — brāhmaṇa; kaścit — some; dāsī-patiḥ — the husband of a low-class woman or prostitute; ajāmilaḥ — Ajāmila; nāmnā — by name; naṣṭa-sat-ācāraḥ — who lost all brahminical qualities; dāsyāḥ — of the prostitute or maidservant; saṁsarga-dūṣitaḥ — contaminated by the association.
Translation: 
In the city known as Kānyakubja there was a brāhmaṇa named Ajāmila who married a prostitute maidservant and lost all his brahminical qualities because of the association of that low-class woman.
Purport: 

The fault of illicit connection with women is that it makes one lose all brahminical qualities. In India there is still a class of servants, called śūdras, whose maidservant wives are called śūdrāṇīs. Sometimes people who are very lusty establish relationships with such maidservants and sweeping women, since in the higher statuses of society they cannot indulge in the habit of woman hunting, which is strictly prohibited by social convention. Ajāmila, a qualified brāhmaṇa youth, lost all his brahminical qualities because of his association with a prostitute, but he was ultimately saved because he had begun the process of bhakti-yoga. Therefore in the previous verse, Śukadeva Gosvāmī spoke of the person who has only once surrendered himself at the lotus feet of the Lord (manaḥ kṛṣṇa-padāravindayoḥ) or has just begun the bhakti-yoga process. Bhakti-yoga begins with śravaṇaṁ kīrtanaṁ viṣṇoḥ, hearing and chanting of Lord Viṣṇu’s names, as in the mahā-mantra — Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare. Chanting is the beginning of bhakti-yoga. Therefore Śrī Caitanya Mahāprabhu declares:

harer nāma harer nāma
 harer nāmaiva kevalam
kalau nāsty eva nāsty eva
 nāsty eva gatir anyathā

“In this age of quarrel and hypocrisy the only means of deliverance is chanting the holy name of the Lord. There is no other way. There is no other way. There is no other way.” The process of chanting the holy name of the Lord is always superbly effective, but it is especially effective in this Age of Kali. Its practical effectiveness will now be explained by Śukadeva Gosvāmī through the history of Ajāmila, who was freed from the hands of the Yamadūtas simply because of chanting the holy name of Nārāyaṇa. Parīkṣit Mahārāja’s original question was how to be freed from falling down into hell or into the hands of the Yamadūtas. In reply, Śukadeva Gosvāmī is citing this old historical example to convince Parīkṣit Mahārāja of the potency of bhakti-yoga, which begins simply with the chanting of the Lord’s name. All the great authorities of bhakti-yoga recommend the devotional process beginning with the chanting of the holy name of Kṛṣṇa (tan-nāma-grahaṇādibhiḥ).