SB 6.17.40
itihasam imam punyam
citraketor mahatmanah
mahatmyam visnu-bhaktanam
srutva bandhad vimucyate
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Citraketu was a great devotee [mahatma]. If one hears this history of Citraketu from a pure devotee, the listener also is freed from the conditional life of material existence.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The historical incidents in the Puranas, such as the history of Citraketu explained in the Bhagavata Purana, are sometimes misunderstood by outsiders, or nondevotees. Therefore Sukadeva Gosvami advised that the history of Citraketu be heard from a devotee. Anything about devotional service or the characteristics of the Lord and His devotees must be heard from a devotee, not from a professional reciter. This is advised herein. Sri Caitanya Mahaprabhu’s secretary also advised that one learn the history of Srimad-Bhagavatam from a devotee: yaha, bhagavata pada vaisnavera sthane. One should not hear the statements of Srimad-Bhagavatam from professional reciters, or else they will not be effective. Quoting from Padma Purana, Sri Sanatana Gosvami has strictly forbidden us to hear about the activities of the Lord and His devotees from the mouths of nondevotees:
avaisnava-mukhodgirnam
putam hari-kathamrtam
sravanam naiva kartavyam
sarpocchistam yatha payah
“One should not hear anything about Krsna from a non-Vaisnava. Milk touched by the lips of a serpent has poisonous effects; similarly, talks about Krsna given by a non-Vaisnava are also poisonous.” One must be a bona fide devotee, and then he can preach and impress devotional service upon his listeners.