O Arjuna, when a properly regulated action is performed because it has to be done, abandoning sanga (delusional clinging) and desire for gain, that renunciation is considered sāttvika.
This is a very sublime, paramount revelation, to be noted with all attention and concern. True relinquishment, says Krishna, does not consist in leaving or not acting, but in living and acting without attachment and desire. How? This is the truth to be grasped by true spiritual enlightenment.
The whole relinquishment is thus a process of getting enlightened about activity and its relevance, not eschewing it altogether. This is, no doubt, a very intriguing statement. Nonetheless, therein lie true spiritual wisdom and relinquishment!
Undue identity towards activity and the clinging to the results it fetches, are the factors causing heaviness and affliction. Once you are able to drop these by proper spiritual enlightenment, activities will be inspiring, relaxing and fulfilling. In this process, ty¡ga is of the false identity with the result and the clinging to desired outcome. Relinquishment happens when ignorance and delusion enslaving the mind are detected and overcome.