योगस्थः कुरु कर्माणि सङ्गं त्यक्त्वा धनञ्जय। सिद्ध्यसिद्ध्योः समो भूत्वा समत्वं योग उच्यते॥

Meaning

Established in yoga, O Dhananjaya, perform your duties having abandoned attachment, remaining equipoised in success and failure alike — this evenness of mind is called yoga. Krishna here distills Karma Yoga into a single sutra: action is unavoidable, but bondage arises only from the ego's craving for a particular fruit. By surrendering the result while sincerely discharging svadharma, the seeker dissolves the dvandvas (pleasure-pain, gain-loss) that otherwise churn the chitta. Samatva — equanimity rooted in the Atman — is itself defined as yoga, the prerequisite to jnana and the gateway to nishkama karma that purifies the heart.