Mentally renouncing all actions, the self-controlled embodied one rests happily in the city of nine gates, neither acting nor causing anyone to act.
Explanation
Krishna continues describing the person who is disciplined and unattached to results. The "city of nine gates" is the body, with its nine openings. Such a person gives up the sense of being the doer (kartṛtva) inwardly, so he stays at peace even while the body acts. Traditions differ on whether this inner renunciation (saṃnyāsa) is compatible with outward activity or points toward formal renunciation.