Chapter 2 · verse 47 · gita.yoga.org

Bhagavad Gita 2.47

कर्मण्येवाधिकारस्ते मा फलेषु कदाचन। मा कर्मफलहेतुर्भूर्मा ते सङ्गोऽस्त्वकर्मणि

Your right is only to work, but not to its results; do not let the results of action be your motive, nor let your attachment be to inaction.