Isa upanishad though found in the mantra section of the Vedas, tells us about the nature of the Self which is neither karaka, Karta or Bhokta or the one for whom we need to do any karma. This Self is Nithya, shuddha, Mukta Swaroopa and shines of its own accord. Such a Self which is ever free & needs no karma to be done) is being expounded in these Mantras. Hence these mantras are not to be considered as part of karma.
The Self pointed in these mantras is utterly distinct from that facet of self which deludes the jiva into action, papa or punya and thereby the endless loop of samsara.
Here nothing needs to be done, instead here the undoing the limitation is the doing. We are already THAT(Praptasya Prapti), we only need to drop the false imagination that we have clinged onto as karta, bhokta (the tadatmya bhava with all such Upadhis). This will dissolve all the barriers, boundaries and one realises that I ALONE am the Self and as the Self i alone pervade all with no exception(Sattvic, rajas, tamasic) in all 3 realms. I am the substratum on which all appear and disappear and i remain unaffected, untouched, unmodified WHOLE alone.
Being Praptasya prapti mere renouncing the veil like the slimy water over the chandan will release forth its fragrance. So when we scrub off the adhyasa/ignorance(sense of individuality by holding on to the kartrutva, bhokrutva bhava) the true nature is revealed by Its own glory. Mental Upasana is a strain or effort and what is already there needs no effort but simply needs us to get rid of the wrong knowledge/ignorance and the Truth stands revealed by itself beyond the subject and object.
