SB 4.22.20
asty eva rajan bhavato madhudvisah
padaravindasya gunanuvadane
ratir durapa vidhunoti naisthiki
kamam kasayam malam antar-atmanah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Sanat-kumara continued: My dear King, you already have an inclination to glorify the lotus feet of the Supreme Personality of Godhead. Such attachment is very difficult to achieve, but when one has attained such unflinching faith in the Lord, it automatically cleanses lusty desires from the core of the heart.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
satam prasangan mama virya-samvido
bhavanti hrt-karna-rasayanah kathah
taj-josanad asv apavarga-vartmani
sraddha ratir bhaktir anukramisyati
(Bhag. 3.25.25)
By association with devotees, dirty things within the heart of a materialistic man are gradually washed away by the grace of the Supreme Personality of Godhead. As silver becomes shiny by being polished, the heart of a materialistic person is cleansed of lusty desires by the good association of devotees. Actually the living being has no connection with this material enjoyment nor with lusty desires. He is simply imagining or dreaming while asleep. But by the association of pure devotees he is awakened, and immediately the spirit soul is situated in his own glory by understanding his constitutional position as the eternal servant of the Lord. Prthu Maharaja was already a self-realized soul; therefore he had a natural inclination to glorify the activities of the Supreme Personality of Godhead, and the Kumaras assured him that there was no chance of his falling victim to the illusory energy of the Supreme Lord. In other words, the process of hearing and chanting about the glories of the Lord is the only means to clarify the heart of material contamination. By the process of karma, jñana and yoga, no one will succeed in driving away contamination from the heart, but once a person takes to the shelter of the lotus feet of the Lord by devotional service, automatically all dirty things in the heart are removed without difficulty.