Bhagavad Gita 18.9
कार्यमित्येव यत्कर्म नियतं क्रियतेऽर्जुन । सङ्गं त्यक्त्वा फलं चैव स त्यागः सात्त्विको मतः ॥
kāryam ity eva yat karma niyataṃ kriyate 'rjuna / saṅgaṃ tyaktvā phalaṃ caiva sa tyāgaḥ sāttviko mataḥ
Translation
The obligatory action that is done because it ought to be done, after letting go of attachment and fruit, that relinquishment is considered to be of the bright kind.
Reflection
Which of your obligations could remain unchanged while your inner relationship to them inverts?
Read this verse in its chapter: Chapter Eighteen
Now the real tyaga. Notice what has not been renounced, the niyatam karma itself. The post stays. What has been let go is two things, sanga, the inward grip, and phala, the appetite for return. The action is done because it is to be done, kartavyam iti. That is the entire interior shift. The same hands do the same work, but the relationship to it has been quietly inverted. The classical renunciate would say leave the field. Krishna says stay on the field and renounce inside. This is harder than walking away. It is also the only renunciation that yields its actual fruit, freedom while still embodied and still engaged.