The mantra 'Om Tat Sat' is a threefold designation of the ultimate reality, Para Brahman, and is rooted in the Bhagavad Gita (17.23), where Lord Krishna declares, 'Om Tat Sat iti nirdesho brahmanas trividhah smritah' — 'Om, Tat, Sat is declared to be the threefold designation of Brahman.' This mantra is used for meditation (dhyana) on the supreme reality, with each syllable representing a distinct aspect: Om as the primordial sound and the universe's essence, Tat as the ultimate truth beyond all conceptualization, and Sat as the absolute existence that is eternal and unchanging. The Upanishads, particularly the Mandukya Upanishad, elaborate on Om as the Pranava, the sound that encompasses all states of consciousness — waking, dreaming, deep sleep, and the fourth (turiya). The syllable 'Tat' is frequently used in Vedantic texts like the Chandogya Upanishad (6.8.7) in the mahavakya 'Tat tvam asi' (That thou art), indicating the identity of the individual self with Brahman. 'Sat' denotes the ultimate reality that is pure being, consciousness, and bliss (Sat-Chit-Ananda). The combined mantra 'Om Tat Sat' is chanted for the contemplation of the supreme reality, leading to the realization of one's true nature and liberation (moksha). Traditionally, this dhyana mantra is recommended for daily practice, ideally at dawn or dusk, in a quiet and clean space. The practitioner may chant it 108 times using a rudraksha mala, focusing on the meaning of each syllable. The mantra is considered safe for all seekers, with no specific cautions, as it is a universal affirmation of truth. It is often recited at the beginning and end of spiritual activities, as prescribed in the Bhagavad Gita (17.24-27), where it is said that acts performed with 'Om Tat Sat' are purified and lead to spiritual merit. This mantra is central to Vedantic study and is used in spiritual retreats and satsangs across India and globally.
Om Tat Sat, the threefold designation of the ultimate reality.