Om Tat Sat

Hari Om Tat Sat (Sanskrit: ओम् तत् सत्, Om Tat Sat ) are the group of three mantras in Sanskrit found in verse 17.23 of the Bhagavad Gita. It means "Om is the mantra of Brahm (ॐ), Tat is the secret mantra of Parbrahm (The Avinashi Narayanaya) and Sat is the secret mantra of Vishnu.[1]

Om tat sat is a Hindu mantra.

"Om Tat Sat" is the eternal sound-pranava. "Om Tat Sat" represents the unmanifest and absolute reality. By the word "reality", here it means total existence. We may even use the word God, reality, existence, Parbrahma or the absolute, are all synonymous terms pointing to one being.

In Bhagavad Gita chapter 17, from verse 23 to 28, Lord Krishna has talked about the meaning & importance of the topic Om Tat Sat. Lord said Om Tat Sat is actually a threefold name of the Supreme soul with which at the start of the universe the Brahman, Vedas and Yajna were made.[2]

"OM" - therefore it is said the priests who japa the veda-mantra as described in the vedas, they always start every activity with the name of the God i.e. "OM".[3]

"Tat" word means everything belongs to the God, by keeping that in mind, the persons seeking liberation selflessly do the yajna, tapas & dana without desiring any of the fruits of the actions.[4]

"Sat" word represents all the actions & duties that are performed with truthfulness, it is also said the everything present in yajna, tapas & dana are considered as "Sat", also actions solely meant for the satisfaction of the supreme is indicated by the word "Sat".[5]