Chapter 3 · The Yoga of Action · Krishna said
Bhagavad Gita 3.25 — The wise work selflessly
सक्ताः कर्मण्यविद्वांसो यथा कुर्वन्ति भारत। कुर्याद्विद्वांस्तथासक्तश्चिकीर्षुर्लोकसंग्रहम् ॥
saktāḥ karmaṇyavidvāṃso yathā kurvanti bhārata | kuryādvidvāṃstathāsaktaścikīrṣurlokasaṃgraham ||
Meaning
Just as the unwise work with attachment, Arjuna, the wise should work without attachment, wishing for the good of the world.