The following is one of the most quoted verses by Srila Prabhupada, from the Srimad Bhagavatam, and it is also one of the longest purports as well. Very important verse!
śrī-prahrādaḥ uvāca—Prahlāda Mahārāja said; śravaṇam—hearing; kīrtanam—chanting; viṣṇoḥ—of LordViṣṇu (not anyone else); smaraṇam—remembering; pāda-sevanam—serving the feet; arcanam—offering worship (with ṣoḍaśopacāra, the sixteen kinds of paraphernalia); vandanaṁ—offering prayers; dāsyam—becoming the servant; sakhyam—becoming the best friend; ātma-nivedanam—surrendering everything, whatever one has; iti—thus; puṁsā arpitā—offered by the devotee; viṣṇau—unto Lord Viṣṇu (not to anyone else); bhaktiḥ—devotional service; cet—if; nava-lakṣaṇā—possessing nine different processes; kriyeta—one should perform; bhagavati—unto the Supreme Personality of Godhead; addhā—directly or completely; tat—that; manye—I consider; adhītam—learning; uttamam—topmost.
Prahlāda Mahārāja said: Hearing and chanting about the transcendental holy name, form, qualities, paraphernalia and pastimes of Lord Viṣṇu, remembering them, serving the lotus feet of the Lord, offering the Lord respectful worship with sixteen types of paraphernalia, offering prayers to the Lord, becoming His servant, considering the Lord one’s best friend, and surrendering everything unto Him (in other words, serving Him with the body, mind and words)—these nine processes are accepted as pure devotional service. One who has dedicated his life to the service of Kṛṣṇa through these nine methods should be understood to be the most learned person, for he has acquired complete knowledge.
When Prahlāda Mahārāja was asked by his father to say something from whatever he had learned, he considered that what he had learned from his spiritual master was the best of all teachings…(from purport)
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