SB 10.10.17

It is said, mahad-vicalanaṁ nṝṇāṁ gṛhiṇāṁ dīna-cetasām (Bhāg. 10.8.4). The only business of a saintly person or sannyāsī, a person in the renounced order, is to preach Kṛṣṇa consciousness. Sādhus, saintly persons, want to preach to both the poor and the rich, but the poor take more advantage of the sādhus’ preaching than the rich do. A poor man receives sādhus very quickly, offers them obeisances, and tries to take advantage of their presence, whereas a rich man keeps a big greyhound dog at his door so that no one can enter his house. He posts a sign saying “Beware of Dog” and avoids the association of saintly persons, whereas a poor man keeps his door open for them and thus benefits by their association more than a rich man does. Because Nārada Muni, in his previous life, was the poverty-stricken son of a maidservant, he got the association of saintly persons and later became the exalted Nārada Muni. This was his actual experience. Therefore, he is now comparing the position of a poor man with that of a rich man.

satāṁ prasaṅgān mama vīrya-saṁvido
bhavanti hṛt-karṇa-rasāyanāḥ kathāḥ
taj-joṣaṇād āśv apavarga-vartmani
śraddhā ratir bhaktir anukramiṣyati
(Bhāg. 3.25.25)

If one gets the advantage of association with saintly persons, by their instructions one becomes more and more purified of material desires.

kṛṣṇa-bahirmukha haiyā bhoga-vāñchā kare
nikaṭa-stha māyā tāre jāpaṭiyā dhare
(Prema-vivarta)

Material life means that one forgets Kṛṣṇa and that one increases in one’s desires for sense gratification. But if one receives the advantage of instructions from saintly persons and forgets the importance of material desires, one is automatically purified. Ceto-darpaṇa-mārjanaṁ bhava-mahā-dāvāgni-nirvāpaṇam (Śikṣāṣṭaka 1). Unless the core of a materialistic person’s heart is purified, he cannot get rid of the pangs of bhava-mahā-dāvāgni, the blazing fire of material existence.