# SB 6.8.42 ## Text > etāṁ vidyām adhigato > viśvarūpāc chatakratuḥ > trailokya-lakṣmīṁ bubhuje > vinirjitya mṛdhe 'surān ## Synonyms *etām*—this; *vidyām*—prayer; *adhigataḥ*—received; *viśvarūpāt*—from the *brāhmaṇa* Viśvarūpa; *śata*-*kratuḥ*—Indra, the King of heaven; *trailokya*-*lakṣmīm*—all the opulence of the three worlds; *bubhuje*—enjoyed; *vinirjitya*—conquering; *mṛdhe*—in battle; *asurān*—all the demons. ## Translation **King Indra, who performed one hundred sacrifices, received this prayer of protection from Viśvarūpa. After conquering the demons, he enjoyed all the opulences of the three worlds.** ## Purport This mystical mantric armor given by Viśvarūpa to Indra, the King of heaven, acted powerfully, with the effect that Indra was able to conquer the *asuras* and enjoy the opulence of the three worlds without impediments. In this regard, Madhvācārya points out: > vidyāḥ karmāṇi ca sadā > guroḥ prāptāḥ phala-pradāḥ > anyathā naiva phaladāḥ > prasannoktāḥ phala-pradāḥ One must receive all kinds of *mantras* from a bona fide spiritual master; otherwise the *mantras* will not be fruitful. This is also indicated in *Bhagavad-gītā* [[bg/4/34|(Bg. 4.34)]]: > tad viddhi praṇipātena > paripraśnena sevayā > upadekṣyanti te jñānaṁ > jñāninas tattva-darśinaḥ "Just try to learn the truth by approaching a spiritual master. Inquire from him submissively and render service unto him. The self-realized soul can impart knowledge unto you because he has seen the truth." All *mantras* should be received through the authorized *guru,* and the disciple must satisfy the *guru* in all respects, after surrendering at his lotus feet. In the *Padma Purāṇa* it is also said, *sampradāya-vihīnā ye mantrās te niṣphalā matāḥ.* There are four *sampradāyas,* or disciplic successions, namely the Brahma-sampradāya, the Rudra-sampradāya, the Śrī sampradāya and the Kumāra-sampradāya. If one wants to advance in spiritual power, one must receive his *mantras* from one of these bona fide *sampradāyas;* otherwise he will never successfully advance in spiritual life. *Thus end the Bhaktivedanta purports of the Sixth Canto, Eighth Chapter, of the* Śrīmad-Bhāgavatam, *entitled "The Nārāyaṇa-kavaca Shield."*