By pleasing the devotee Bhagavata one can receive the benefit of the book Bhagavata. Human reasoning fails to understand how by serving the devotee Bhagavata or the book Bhagavata one gets gradual promotion on the path of devotion.
Only one who has properly grasped the transcendental knowledge from the right source by submissive hearing can properly explain the subject.
One can assimilate the knowledge of the revealed scriptures only by hearing and explaining.
No one should be allowed to sit on the vyasasana who is not spotless in character and who is not freed from the above-mentioned vices. He not only should be freed from all such vices, but must also be well versed in all revealed scriptures or in the Vedas.