तस्मादसक्तः सततं कार्यं कर्म समाचर।असक्तो ह्याचरन्कर्म परमाप्नोति पूरुषः॥
tasmād asaktaḥ satataṃ kāryaṃ karma samācaraasakto hyācaran karma param āpnoti pūruṣaḥ
Word by word
The verse says
So do the work that is there to be done, always, without holding on to it. Acting without holding on, a person reaches what is highest.
In plain words
Tasmāt — therefore. And the therefore does not follow from the two verses before it.
He has just described someone with no duties. Now he says: so work, always, unattached.
The argument has jumped, and the jump is the teaching.
Where you've felt this · at work
Someone who no longer needs the job keeps doing it, properly, at the same standard. They are not trapped and everyone can see they are not. That is precisely what makes the work land differently.
Going deeper
The logical gap here is deliberate and it is the hinge of the chapter.
Verses 17 and 18 describe someone exempt from action. Verse 19 says therefore act. The conclusion does not follow from the exemption — it follows from everything before it, and the exemption has been set aside.
What has quietly happened is a change of subject. The question was must I act? Krishna has answered it as fully as it can be answered: no, not if you need nothing. And then he moves to the question that was actually live: given that you are not that person, how?
Asaktaḥ — unattached — is the answer, and it is the same word from verse 7 and the same idea as 2.47.
The promise attached is the largest in the chapter: param āpnoti — he reaches the highest. Not a good outcome. The highest. Krishna is saying that ordinary work, done without grabbing at it, goes all the way.
That is the Gita's central democratic claim, and it is why the book left the forest behind.