सर्वकर्माणि मनसा संन्यस्यास्ते सुखं वशी।नवद्वारे पुरे देही नैव कुर्वन्न कारयन्॥
sarva-karmāṇi manasā sannyasyāste sukhaṃ vaśīnava-dvāre pure dehī naiva kurvan na kārayan
Word by word
The verse says
Having set all actions down with the mind, the embodied one rests happily in the city of nine gates, neither acting nor causing action.
In plain words
A body described as a walled town with nine ways in and out.
Two eyes, two ears, two nostrils, a mouth, and the two lower openings. Nine.
And the one who lives there is described as a resident, not an owner.
Where you've felt this · in health
You rent the same flat for six years. You fix the tap, paint the hall and come to love the light in it at four o'clock. You have also never once confused it with being your flat.
Going deeper
Nava-dvāre pure — in the city of nine gates. It is an old image and it is doing precise work.
A city is not a disguise or a prison. It is somewhere you live, with a wall and gates, and things come in and go out through them continuously. Nothing about the picture is hostile to the body.
What it does establish is a distinction between the place and the resident. The gates are the senses, which the last few verses have been describing as busy on their own account. The one who dwells there is not identical with the traffic.
Āste sukham — sits happily, rests at ease. This is not a picture of someone enduring the body or waiting to be free of it.
And that is worth holding on to, because the Gita is often read as hostile to embodiment. Here the recommended posture toward your own body is roughly that of a good tenant: attentive, careful with it, not confused about the deeds.