Bhagwad Gita - Post 214

Verse 26

  

The word Sat is used in the sense of reality and of goodness; and so also, O Arjuna, it is used in the sense of an auspicious act!

Sat is used to mean both reality and goodness.. It is also used for all praise-worthy actions. In our everyday contact with the world, we live in a realm of relative reality and a seeker is apt to take the world perceived, felt and thought of --- through the play of his body, mind and intellect equipment --- as absolutely real. Therefore the term Sat is often used to remind us that all these relative realities have the self-same substratum Sat, the Absolute Reality.

  

Verse 27

  

Steadfastness in sacrifice, austerity and gift, is also called Sat, and also action in connection with these (or for the sake of the Supreme) is called Sat.

Chinmaya says,

“The term Sat is used to indicate a man's faith and devotion in sacrifice, austerity and gift. Thus Sat registers one's faith in the principles underlying Yajna, Daana and Tapas and also in his various acts of sacrifice (Yajna), charity (Daana) and austerity (Tapas).

In short, even acts of sacrifice and austerity, when they are not of the Sattwic type can be rendered "good," when they are pursued with this required inner attunement which is gained by invoking in the performer's bosom the concept of --- the Supreme (OM), the Universal (Tat), and the Real (Sat) --- the Infinite Brahman. 

If these chantings are undertaken with faith and sincerity the seeker's mind expands and gives up all its selfishness and arrogance. Ego and ego-centric desires bring about attachments, which, in their turn, destroy the freedom of the individual to grow into the ampler field of joy of the Spirit.

To cut off these shackles which are forged in the fields of activity, we have to re-enter the very "realm-of-action" and persuade ourselves to perform such 'right' Karmas as will liquidate the bad reactions (Karma-Phala), of the 'wrong' actions of the past. 

This unwinding of the vasanas, the very creators of our psychological imperfections, can be effected only in the field-of-activity. This is accomplished by an intelligent, right adjustment of our mental attitude all along, when we are at work. 

The required changes are brought about by the remembrance of the Infinite Reality as indicated by the three terms "OM-TAT-SAT." The fundamental principle is that the actions can leave behind only such reactions as are ordered by the type of motives and attitudes of the performer.”

Thus, the threefold definition of Brahman—Om Tat Sat—means God here, God above and God below, and God everywhere. The everywhereness of God includes the aboveness and the hereness of God. The aboveness is Tat, the hereness is Sat, and the everywhereness is Om. Therefore, Om Tat Sat is a complete mystical symbol which was evolved by ancient Masters. This is why in all auspicious beginnings, Om is chanted; and when we conclude anything, we say Om Tat Sat, dedicating the performance to the Almighty.

Love.