Mahanarayana Upanishad

The Mahanarayana Upanishad (Sanskrit: महानारायण उपनिषद्, IAST: Mahānārāyaṇa Upaniṣad), also Brihannarayana Upanishad, is an ancient Sanskrit text, and is one of the minor Upanishads of Hinduism. The text is classified as a Vaishnava Upanishad.

The text exists in three main versions. One version with 64 chapters is attached to the Krishna Yajurveda in several South Indian anthologies, and the same text in Andhra edition exists in an expanded form with 80 chapters attached to the same Veda. A second version is attached to the Atharvaveda, has 25 chapters and is prefixed with Tripadvibhuti. These manuscripts are sometimes titled as the Yajniki Upanishad or Tripad-vibhuti-mahanarayana Upanishad. According to Swami Vimalananda, this Upanishad is also called Yagniki Upanishad in reverence for sage Yagnatma Narayana.

Author Doris Srinivasan says, The Upanishad, despite its title which means "Great Narayana", is notable for glorifying both Narayana and Rudra, both as the first equivalent embodiment of Brahman, the concept of ultimate, impersonal, and transcendental reality in Hinduism. The Upanishad uses Vedanta terminology, and uses numerous fragments from Rigveda, Taittiriya Brahmana, Vajasaneyi Samhita and Principal Upanishads.

When doing sandhyavandanam, the mantras used for Prāṇāyāma, Mantrācamana, Gāyatrī āhvānam, Devatānamaskāraḥ and Gāyatrī Prasthānam are directly from Mahanarayana Upanishad (Andhra rescension containing 80 anuvakas).