Ch 18, Sh 3-6, Bhagawad Gita, Shankar Bhashya

No one can point an exception to the proposition that 'having given up all actions mentally, (the embodied man of self-control) continues happily৷৷.without doing or causing (others) to do anything at all' (see 5.13). Therefore these alternative veiws regarding sannyasa and tyaga are concerned only with those who are qualified for rites and duties. But the enlightened ones who have realized the supreme Truth are competent only for steadfastness in Knowledge, which is characterized by renunciation of all actions; not for anything else. Hence, they do not come within the purview of the alternative veiws. Thus has this been pointed out by us in connection with the text, '৷৷.he who knows this One as indestructible৷৷.' (2.21) as also in the beginning of the third chapter.
Bharata-sattama, O the most excellent among the descendants of Bharata; srnu, hear, understand; me, from Me, from My statement; niscayam, the firm conclusion; tatra tyage, regarding that tyaga, regarding these alternative veiws on tyaga and sannyasa as they have been shown. Hi, for; purusavyaghra, O greatest among men; tyagah, tyaga; samprakirtitah, has been clearly declared, has been distinctly spoken of in the scriptures; to be trividhah, of three kinds, threefold, under the classes of tamasa (those based on tamas etc. The Lord has used the word tyaga with the idea that the (primary) meanings of tyaga and sannyasa are verily the same. Since it is difficult to comprehend this idea, that the primary meanings of the words tyaga and sannyasa can be threefold under the classification based on tamas etc. in the case of one who is unenlightened and who is alified for rites and duties-but not in the case of one who has realized the supreme Goal-,therefore no one else is capable of speaking the truth in this connection. Hence, listen to the firm conclusion of the Lord with regard to the supreme Truth as revealved by the scriptures. Which, again, is this firm conclusion? In reply the Lord says:
Yajna-dana-tapah-karma, the practice of sacrifice, charity and austerity-this threefold practice; na tyajyam, is not to be abandoned; tat, it; is eva, surely; karyam, to be undertaken. Why? Yajnah, sacrifice; danam, charity; and tapah, austerity; are eva, verily; pavanani, the purifiers, the causes of sanctification; manisinam, of the wise, i.e. of those who do not seek results for themselves.
Tu, but; api, even; etani, these; karmani, actions, viz sacrifice, charity and austerity, which have been spoken of as purifiers; kartavyani, have to be undertaken; tyaktva, by renouncing; sangam, attachment to them; and by giving up (hankering for) their phalani, results. Iti, this; is me, My; niscitam, firm; and uttamam, best; matam, conculsion. Having promised, 'hear from Me the firm conclusion regarding that (tyaga)' (4) and also adduced the reason that they are purifiers, the utterance, 'Even these actions have to be performed. This is the firm and best conclusion', is only by way of concluding the promised subject-matter; this sentence does not introduce a fresh topic. For it stands to reason that the phrase 'even these' refers to some immediate topic under discussion. The implication of the word api (even) is: 'Even these acts, which are causes of bondage to one who has attachment and who hankers after their results, have to be undertaken by a seeker of Moksha.' But the phrase 'even these' is not used in relation to other acts.