Gita 2.47 · Sankhya Yoga
कर्मण्येवाधिकारस्ते मा फलेषु कदाचन ।मा कर्मफलहेतुर्भूर्मा ते सङ्गोऽस्त्वकर्मणि ॥
karmaṇy evādhikāras te mā phaleṣu kadācanamā karma-phala-hetur bhūr mā te saṅgo 'stv akarmaṇi
You have a right to your work, but never to its results. Do not act for the reward, and do not cling to doing nothing.