Bhagwad Gita
Chapter 4, Verse 22
यदृच्छालाभसन्तुष्टो द्वन्द्वातीतो विमत्सरः।
समः सिद्धावसिद्धौ च कृत्वापि न निबध्यते।।4.22।।
He who is satisfied with gain which comes of its own accord, who is free from duality and does not envy, who is steady both in success and failure, is never entangled, although performing actions.