Ch 18, Sh 48 continued-4, Sh 49 Bhagawad Gita, Shankar Bhashya

Even the theory of transformation held by the Sankhyas does not differ from the standpoint of the Vaisesikas, since they believe in the origination of some new attribute [i.e. in the origination of a transformation that did not exist before.] and its destruction. Even if manifestation and disappearance of anything be accepted, yet there will be contradiction with valid means of knowledge as before in the explanation of existence or non-existence of manifestation and disappearance. Here is also refuted the idea that origination etc. (of an effect) are merely particular states of its cause. As the last alternative, it is only the one entity called Existence that is imagined variously through ignorance to be possessed of the states of origination, destruction, etc. like an actor (on a stage). This view of the Lord has been stated in the verse, 'Of the unreal there is no being৷৷.' (2.16). For, the idea of existence is constant, while the others are inconstant.
Objection: If the Self be immutable, then how does the 'renunciation of all actions' become illogical?
Vedantin: If the adjuncts (i.e. body and organs) be real or imagined through ignorance, in either case, action, which is their attribute, is surely superimposed on the Self through ignorance. From this point of view it has been said that an unenlightened person is incapable of totally renouncing actions even for a moment (cf. 3.5). The enlightened person, on the other hand, can indeed totally renounce actions when ignorance has been dispelled through Illumination; for it is illogical that there can (then) remain any trace of what has been superimposed through ignorance. Indeed, no trace remains of the two moons, etc. superimposed by the vision affected by (the disease called) Timira when the disease is cured. This being so, the utterance, 'having given up all actions mentally' (5.13), etc. as also, 'Being devoted to his own duty' (45) and 'A human being achieves 'success by adoring Him through his own duties (46), becomes justifiable. What was verily spoken of as the success arising from Karma (yoga), characterized as the fitness for steadfastness in Knowledge, the fruit of that (fitness), characterized as 'steadfastness in Knowledge' consisting in the perfection in the form of the state of one (i.e. a monk) free from duties, has to be stated.
Hence the (following) verse is begun:
Asakta-buddhih, he whose intellect, the internal organ, remains unattached; sarvatra, to everything, with regard to son, wife and others who are the causes of attachment; jitatma, who has conquered his internal organs; and vigata-sprhah, who is desireless, whose thirst for his body, life and objects of enjoyment have been eradicated; he who is such a knower of the Self, adhigaccahti, attains; sannyasena, through monasticism, through perfect knowledge or through renunciation of all actions preceded by this knowledge; the paramam, supreme, most excellent; naiskarmya-siddhim, perfection consisting in the state of one free from duties.