The different Gāyatrīs.: The Gāyatrīs too of these forms shall be evolved, the deities shall be installed and worshipped. Perfect knowledge, yantras, mantras and the Upaniṣads (esoteric doctrines) are the secret of Viṣṇu, Nārāyaṇa the lord of Devas. Born of the five Brahmāṅgas[5] they are identical with the five Bhūtas. The mantra of Viṣṇu viz., “Namo Nārāyaṇāya” prefixed with the Praṇava is highly auspicious. It consists of eight syllables.