BG 17.25-27
With the pronunciation of " Tat " and without aiming at fruit are performed the various acts of sacrifice, austerity and gift, by those desiring liberation. " Sat " is used in the sense of reality and goodness; likewise, O Pârtha, the word " Sat " is used in the sense of a good work. Steadfastness in sacrifice, austerity and gift is also called " Sat ", and action for the sake of the Supreme is also named " Sat."