Chapter 18, Verse 9
Part of 18: Mokṣha Sanyās Yog — मोक्षसंन्यासयोगकार्यमित्येव यत्कर्म नियतं क्रियतेऽर्जुन।सङ्गं त्यक्त्वा फलं चैव स त्यागः सात्त्विको मतः॥
kāryam ity eva yat karma niyataṁ kriyate ‘rjuna saṅgaṁ tyaktvā phalaṁ chaiva sa tyāgaḥ sāttviko mataḥ
Whatever obligatory action is done, O Arjuna, merely because it ought to be done, abandoning attachment and also the desire for reward, that renunciation is regarded as sattvic (pure).
A man of pure nature performs actions that have fallen to his lot in accordance with his capacity and his inherent nature. He is not filled with the pride that he is the performer of such actions nor does he hope for any gain therefrom. An ignorant man may think that the obligatory duties may produce their fruits for the performer by causing selfpurification and preventing the sin of omission or nonperformance. This sort of thinking and expectation of rewards also must be abandoned. Abandonment of the rewards of actions is praised in this verse. When a man does obligatory duties without agency and with unselfishness and egolessness his,mind is purified, his Antahkarana is prepared for the reception of the divine light or the dawn of Selfknowledge. He gradually becomes fit for devotion to knowledge (JnanaNishtha). The aspirant or seeker after liberation should be prepared to undergo physical sufferings. All acts of selfdiscipline and selfsacrifice entail physical suffering. This, again, is the central teaching of the Gita -- do your duty without attachment and selfish desires.