योगस्थः कुरु कर्माणि सङ्गं त्यक्त्वा धनञ्जय । सिद्ध्यसिद्ध्योः समो भूत्वा समत्वं योग उच्यते ॥ ४८ ॥
yoga-sthaḥ kuru karmāṇi saṅgaṁ tyaktvā dhanañjaya siddhy-asiddhyoḥ samo bhūtvā samatvaṁ yoga uchyate
Translation
Established in yoga, perform your actions, O Dhananjay, abandoning attachment and remaining even-minded in success and failure. This evenness of mind is called yoga.
Hindi Meaning (हिंदी अर्थ)
हे धनंजय! आसक्ति को त्यागकर, सफलता और असफलता में समान रहते हुए, योग में स्थित होकर कर्म करो। यह समत्व ही योग कहलाता है।
Commentary
Samatvaṁ yoga uchyate — "equanimity is yoga" — is the Gita's first definition of yoga. It has nothing to do with posture or retreat; it is a quality of mind in the middle of action. A person who works with full effort but stays balanced whether it succeeds or fails is practising yoga.