Bhagavad Gita Chapter 5, Verse 11

कायेन मनसा बुद्ध्या केवलैरिन्द्रियैरपि | योगिनः कर्म कुर्वन्ति सङ्गं त्यक्त्वाऽत्मशुद्धये ||

kāyena manasā buddhyā kevalair indriyair api yoginaḥ karma kurvanti saṅgaṁ tyaktvātmaśuddhaye

The yogis perform actions with body, mind, intellect, and even with the senses alone, having abandoned attachment, for self-purification.

Krishna describes how yogis perform actions: they use body (kāyena), mind (manasā), intellect (buddhyā), and senses (indriyaiḥ) to perform actions, but they've abandoned attachment (saṅgaṁ tyaktvā). The key phrase is 'ātmaśuddhaye'—for self-purification. This means yogis don't act for personal gain or to satisfy desires—they act for purification of the self. Actions are performed using all instruments—body, mind, intellect, senses—but without attachment to results. This is the practical method of karma yoga: use all your faculties, but act for purification, not for personal benefit.