Bhagavad Gita 18.6

एतान्यपि तु कर्माणि सङ्गं त्यक्त्वा फलानि च।कर्तव्यानीति मे पार्थ निश्िचतं मतमुत्तमम् ॥१८.६॥

etānyapi tu karmāṇi saṅgaṃ tyaktvā phalāni cakartavyānīti me pārtha niśicataṃ matamuttamam

But even these actions should be performed, leaving aside attachment and the desire for rewards, O Arjuna; this is my certain and most assured conviction.

गीता