The result, of discharging duty without expecting its fruit, will be that he will not develop new attachment, as he does not perform actions for himself; and old attachment will perish, by doing good to others. By performing actions, his impulse for actions will also disappear. Thus renunciation of attachment, will spontaneously lead to salvation. The desire, to get hold of the perishable is bondage, and to renounce this desire is, emancipation. The method to attain emancipation, is that one should not depend on the perishable viz., should not have any affinity for it.
Karyam karma karoti yah:—'Karyam and 'duty' are synonyms. What can be easily performed, is a must, and what can never and be forsaken, is called a duty. Discharge of duty is not impossible, not even hard. What ought not to be done, is not duty, it is 'Akartavya (that should not be done). Activities, which ought not to be done are of two types. (1) Those that are beyond our capacity. (2) Those which are forbidden by scriptures and traditions. Such activities, are never to be done. The gist is, that we should resort to prescribed duties without expecting any return, with a detached spirit, for the welfare of others. One should, discharge one's duty, in accordance with the ordinance of scriptures, for the welfare of others and without expecting its fruit, in order to do away with attachment for action, as well as its fruit. Actions, are performed, with two attitudes of mind—for obtaining worldly things and for wiping out attachment for actions and their fruits. The inspiration to perform actions, with the latter attitude, is given here.
Sa sannyasi ea yogi ea:—He who, discharges his duty in the above mentioned way, is a Sannyasi and a Yogi. He is a Sannyasi, because he discharges his duty without attachment for action and its fruit and is a Yogi, because he remains equanimous in pleasure and pain, while discharging his duty.
His sense, of doership and enjoyership, is destroyed by doing actions without expecting any reward. Thus all his links with ctions, and the fruits are, totally cut asunder. Therefore, that Karmayogi has been called a 'Sannyasi.'
Arjuna thought it better to renounce the physical performance of actions and thus be a Sannyasi. So, in 2/5, Arjuna said, that it was better to live on alms, than to wage war. So Lord Krsna, says to Arjuna, "O Arjuna, the conception you have about a Sannyasi is not right. He, who discharges his duty for duty's sake, without being attached to the fruit of action, is a real Sannyasi."