Bhagavad Gita Chapter 5, Verse 13

सर्वकर्माणि मनसा संन्यस्यास्ते सुखं वशी | नवद्वारे पुरे देही नैव कुर्वन्न कारयन् ||

sarva-karmāṇi manasā sannyasyāste sukhaṁ vaśī navadvāre pure dehī naiva kurvan na kārayan

The embodied soul, having renounced all actions by the mind, dwells happily in the nine-gated city (body), neither acting nor causing action.

Krishna describes the state of the yogi who has renounced all actions by the mind (manasā sannyasyāste): the embodied soul (dehī) dwells happily (sukhaṁ) in the nine-gated city (navadvāre pure)—the body with its nine openings (two eyes, two ears, two nostrils, mouth, and two lower openings). The yogi neither acts (na kurvan) nor causes action (na kārayan). This is the state of complete inner renunciation—the mind has renounced attachment to action, so the yogi acts without the sense of doership. The body continues to function, but the mind is free from attachment. This is the practical meaning of 'renunciation by the mind'—not physical inaction, but mental detachment.