Chapter II · Śloka 50
बुद्धियुक्तो जहातीह उभे सुकृतदुष्कृते |
तस्माद्योगाय युज्यस्व योगः कर्मसु कौशलम् ||
तस्माद्योगाय युज्यस्व योगः कर्मसु कौशलम् ||
buddhi-yukto jahātīha ubhe sukṛta-duṣkṛte |
tasmād yogāya yujyasva yogaḥ karmasu kauśalam ||
tasmād yogāya yujyasva yogaḥ karmasu kauśalam ||
One who is united with the intellect casts off here both good and evil deeds. Therefore yoke yourself to yoga; yoga is skill in action.
The most celebrated definition of yoga in the Gita: not withdrawal from action but mastery of it — acting from the still centre so that neither merit nor demerit accumulates. The word kauśalam implies both dexterity and cleanness of execution.