तस्मादसक्तः सततं कार्यं कर्म समाचर। असक्तो ह्याचरन्कर्म परमाप्नोति पूरुषः ॥

tasmād asaktaḥ satataṁ kāryaṁ karma samāchara asakto hyācharan karma param āpnoti pūruṣhaḥ

Therefore, without attachment, constantly perform action which is duty, for, by performing action without attachment, man verily reacheth the Supreme.

In plain words: So Krishna tells Arjuna to always do his duty without attachment. Working this way, a person reaches the Supreme, God.