2.50 Listen to the result that one possessed of the wisdom of eanimity attains by performing one's own duties: Buddhi-yuktah, possessed of wisdom, possessed of the wisdom of eanimity; since one jahati, rejects; iha, here, in this world; ubhe, both; sukrta-duskrte, virtue and vice (righteousness and unrighteousness), through the purification of the mind and acisition of Knowledge; tasmat, therefore; yujyasva, devote yourself; yogaya, to (Karma-) yoga, the wisdom of eanimity. For Yoga is kausalam, skilfulness; karmasu, in action. Skilfulness means the attitude of the skilful, the wisdom of eanimity with regard to one's success and failure while engaged in actions (karma)  called one's own duties (sva-dharma)  with the mind dedicated to God.
That indeed is skilfulness which, through eanimity, makes actions that by their very nature bind give up their nature! Therefore, be you devoted to the wisdom of eanimity.