प्रकृत्यैव च कर्माणि क्रियमाणानि सर्वशः।यः पश्यति तथाऽऽत्मानमकर्तारं स पश्यति॥
prakṛtyaiva ca karmāṇi kriyamāṇāni sarvaśaḥyaḥ paśyati tathātmānam akartāraṃ sa paśyati
Word by word
The verse says
Whoever sees that actions are performed in every way by nature alone, and that the self is not the doer — that person sees.
In plain words
The sharpest version of the claim, and it is easy to misuse.
Actions are performed by nature. The self does not act.
Said by the man who, three chapters ago, told Arjuna to pick up his bow.
Where you've felt this · in sport
A keeper who takes a reflex catch cannot tell you what he did. The hand went. He has spent fifteen years making that hand, and in the half-second that mattered there was nobody at home deciding anything.
Going deeper
Read in isolation this verse excuses anything, and read in context it does not, and the honest thing is to say both.
If the self is never the doer, then nobody is answerable for anything — and the verse has been quoted that way. What rules it out is the book it sits in. Eighteen chapters are spent telling one man how to act well, which would be empty instruction if action were nobody's.
The traditions handle this differently and the disagreement is real. Some take it as an account of how things are once the sense of doership has gone, not as a licence for somebody who still has it. Others read it as a claim about nature's machinery that leaves human responsibility intact at a different level.
What can be said plainly is that the man hearing it is immediately told to fight, and is held responsible throughout for how. Whatever this verse removes, it does not remove that.