Bhagavad Gita Chapter 4.22
nirāśīr yata-cittātmā
tyakta-sarva-parigrahaḥ
śārīraḿ kevalaḿ karma
kurvan nāpnoti kilbiṣam
Translation
He who is satisfied with gain which comes of its own accord, who is free from duality and does not envy, who is steady in both success and failure, is never entangled, although performing actions.