SB 6.8: The Nārāyaṇa-kavaca Shield
This chapter describes how Indra, the King of heaven, was victorious over the soldiers of the demons, and it also describes the shield of the Viṣṇu mantra.
To take protection from this shield, one must first touch kuśa grass and wash one’s mouth with ācamana-mantras. One should observe silence and then place the eight-syllable Viṣṇu mantra on the parts of his body and place the twelve-syllable mantra on his hands. The eight-syllable mantra is oṁ namo nārāyaṇāya. This mantra should be distributed all over the front and back of the body. The twelve-syllable mantra, which begins with the praṇava, oṁkāra, is oṁ namo bhagavate vāsudevāya. One syllable should be placed on each of the fingers and should be preceded by the praṇava, oṁkāra. Thereafter, one must chant oṁ viṣṇave namaḥ, which is a six-syllable mantra. One must progressively place the syllables of the mantra on the heart, the head, between the two eyebrows, on the śikhā and between the eyes, and then one should chant maḥ astrāya phaṭ and with this mantra protect himself from all directions. Nādevo devam arcayet: one who has not risen to the level of a deva cannot chant this mantra. According to this direction of the śāstra, one must think himself qualitatively nondifferent from the Supreme.
After finishing this dedication, one must offer a prayer to the eight-armed Lord Viṣṇu, who sits on the shoulders of Garuḍadeva. One also has to think of the fish incarnation, Vāmana, Kūrma, Nṛsiṁha, Varāha, Paraśurāma, Rāmacandra (the elder brother of Lakṣmaṇa), Nara-Nārāyaṇa, Dattātreya (an empowered incarnation), Kapila, Sanat-kumāra, Hayagrīva, Nāradadeva (the incarnation of a devotee), Dhanvantari, Ṛṣabhadeva, Yajña, Balarāma, Vyāsadeva, Buddhadeva and Keśava. One should also think of Govinda, the master of Vṛndāvana, and one should think of Nārāyaṇa, the master of the spiritual sky. One should think of Madhusūdana, Tridhāmā, Mādhava, Hṛṣīkeśa, Padmanābha, Janārdana, Dāmodara and Viśveśvara, as well as the Supreme Personality of Godhead Kṛṣṇa Himself. After offering prayers to the Lord’s personal expansions known as the svāṁśa and śaktyāveśa-avatāras, one should pray to the weapons of Lord Nārāyaṇa, such as the Sudarśana, gadā, śaṅkha, khaḍga and bow.
After explaining this process, Śukadeva Gosvāmī told Mahārāja Parīkṣit how Viśvarūpa, the brother of Vṛtrāsura, described the glories of the Nārāyaṇa-kavaca to Indra.