Bhagavad Gita 3.19
तस्मादसक्त: सततं कार्यं कर्म समाचार |
असक्तो ह्यचरन्कर्म परमाप्नोति पुरुष:
Translation
Therefore, giving up attachment, perform actions as a matter of duty because by working without being attached to the fruits, one attains the Supreme.