अनादित्वान्निर्गुणत्वात्परमात्मायमव्ययः।शरीरस्थोऽपि कौन्तेय न करोति न लिप्यते॥
anāditvān nirguṇatvāt paramātmāyam avyayaḥśarīra-stho ’pi kaunteya na karoti na lipyate
Word by word
The verse says
Because it is without beginning and without the three strands, this supreme self does not perish. Though it dwells in the body, Arjuna, it does not act and it is not stained.
In plain words
Na karoti na lipyate — it does not act, and it is not stained.
The second word is the interesting one. Lipyate is what happens to a surface when something sticks to it.
Not protected from staining. Not the kind of thing anything can stick to.
Where you've felt this · in health
You can throw mud at a window and at an open doorway. The window needs cleaning afterwards. The doorway is in exactly the same condition it was in before, and nobody had to wipe it.
Going deeper
Being unstainable by nature is different from being kept clean, and the distinction carries real weight.
A thing that can be stained and is being protected requires vigilance; the protection could fail. What is described here cannot take a mark at all, because there is no surface for one to sit on. That removes a whole anxious project — the business of keeping something pure.
The next verse gives the image that makes this concrete, and it is the best one in the chapter.
What it implies for a reader is a strange consolation. Whatever you have done, and whatever has been done to you, the thing this chapter has been pointing at throughout has not been altered by any of it. That is not an argument that the past does not matter. It is an argument about where the damage actually landed, and it did not land there.