तदित्यनभिसन्धाय फलं यज्ञतपःक्रियाः।
दानक्रियाश्च विविधाः क्रियन्ते मोक्षकाङ्क्षि।।17.25।।
17.25 After (uttering) the word tat, acts of sacrifice and austerity as also the various acts of charity are performed without regard for results by persons aspiring for Liberation.
17.25 Whatever acts such as the study of the Vedas, sacrifices, austerities and gifts are done without aiming at results by those of the first three stations, seeking only final release - these are designated by the term Tat referring to the brahman, since they constitute the means for attainment of brahman. For it is well known that the term Tat signifies brahman, as in the following passage: He is Sah,Vah, Kah, Kim, Yat, Tat, Padam, Anuttamam. (M.B., 13.254.91). Thus, the study of the Vedas, sacrifices etc., which are the means of attaining release, have been stated; the connection of Tat has been spoken of since the word Tat signifies them (i.e., the study of Vedas etc.). The connection of the term Tat with the three stations is shown because of their practising the study of the Vedas etc., in the way stated. In order to show how the term Sat is connected with these, Sri Krsna shows the etymology of the term Sat, as it is prevalent in the world:
Tadityanabhisandhaaya phalam yajnatapah kriyaah; Daanakriyaashcha vividhaah kriyante mokshakaangkshibhih.
tat—the syllable Tat; iti—thus; anabhisandhāya—without desiring; phalam—fruitive rewards; yajña—sacrifice; tapaḥ—austerity; kriyāḥ—acts; dāna—charity; kriyāḥ—acts; cha—and; vividhāḥ—various; kriyante—are done; mokṣha-kāṅkṣhibhiḥ—by seekers of freedom from material entanglements