The mantra 'Om Tat Sat' is a threefold designation of the ultimate reality, Para Brahman, as declared in the Bhagavad Gita (17.23): 'Om Tat Sat iti nirdesho brahmanas trividhah smritah' — 'Om, Tat, Sat — this has been declared as the threefold designation of Brahman.' This dhyana mantra is used for deep contemplation on each syllable, leading to non-dual realization. 'Om' represents the primordial sound, the source of all creation, and is analyzed phonetically as A-U-M, encompassing the three states of waking, dreaming, and deep sleep, as per the Mandukya Upanishad. 'Tat' (That) points to the transcendental, indescribable ultimate truth, beyond all attributes. 'Sat' denotes absolute existence, the unchanging reality that underlies all phenomena. The combination of these three terms forms a powerful beej-akshara (seed syllable) mantra for meditation on the non-dual Brahman. According to the Bhagavad Gita (17.24-27), the utterance of 'Om Tat Sat' sanctifies acts of sacrifice, charity, and austerity, and is used by seekers of liberation to align their actions with the supreme. The traditional purpose of this mantra is to dissolve the duality between the meditator and the object of meditation, leading to the direct experience of oneness with Brahman. It is chanted during japa (repetition) or dhyana (meditation) in a quiet setting, ideally at dawn or dusk, with a count of 108 times using a rudraksha mala. The mantra is considered safe for all practitioners, as it is purely vedantic in nature, but it is recommended to receive initiation (diksha) from a qualified guru to understand its deeper significance. The Upanishads, such as the Taittiriya Upanishad (1.5), also expound on 'Sat' as the ultimate reality, and 'Om' as the symbol of Brahman. This mantra is central to Vedantic study and is often recited during spiritual retreats and satsangs. It is worshiped pan-India and globally by followers of Advaita Vedanta. The mantra's power lies in its ability to quiet the mind and reveal the non-dual nature of existence, as emphasized in the Bhagavad Gita and the Upanishads.
Om Tat Sat, the threefold designation of the ultimate reality.