3.19
तस्मादसक्तः सततं कार्यं कर्म समाचर | असक्तो ह्याचरन्कर्म परमाप्नोति पूरुषः ||१९||
tasmād asaktaḥ satataṁ kāryaṁ karma samāchara asakto hy ācharan karma param āpnoti pūruṣhaḥ
Translation
Therefore, without being attached to the fruits of activities, one should act as a matter of duty, for by working without attachment one attains the Supreme.
Interpretation
The central directive of karma yoga: act constantly ('satatam' — always, continuously) but without attachment. Perform action as duty, not as a means to personal gain. This is the paradox of the karma yogi: they work harder than ordinary people (constantly) but are freer than anyone (because they are not bound by the results).