aham vedmi suko vetti
vyaso vetti na vetti va
bhaktya bhagavatam grahyam
na buddhya na ca tikaya
aham—I (Lord Siva); vedmi—know; sukah—Sukadeva Gosvami; vetti—knows; vyasah—Vyasadeva; vetti—knows; na vetti va—or may not know; bhaktya—by devotional service (executed in nine different processes); bhagavatam—the Bhagavata Purana (called Paramahamsa-samhita, the text or treatise readable by the topmost transcendentalists); grahyam—to be accepted; na—not; buddhya—by so-called intelligence or experimental knowledge; na—nor; ca—also; tikaya—by imaginary commentary.
"[Lord Siva said,] 'I may know; Sukadeva Gosvami, the son of Vyasadeva, may know; and Vyasadeva may know or may not know the Srimad Bhagavatam. On the whole, Srimad-Bhagavatam, the spotless Purana, can be learned only through devotional service, not by material intelligence, speculative methods or imaginary commentaries.' "
Devotional service includes nine processes, beginning with hearing, chanting and remembering the activities of Lord Visnu. Only one who has taken to devotional service can understand Srimad-Bhagavatam, which is the spotless Purana for a transcendentalist (paramahamsa). So-called commentaries are useless for this purpose. According to the Vedic injunction: yasya deve para bhaktir yatha deve tatha gurau. All Vedic literatures maintain that Srimad-Bhagavatam has to be learned from the person bhagavata, and to understand it one has to engage in pure devotional service. Srimad-Bhagavatam cannot be understood by so-called erudite scholars or grammarians. One who has developed pure Krsna consciousness and has served the pure devotee, the spiritual master, can understand Srimad-Bhagavatam. Others cannot.
Link to this page: https://prabhupadabooks.com/cc/madhya/24/313