Chapter 14 · verse 16 · gita.yoga.org

Bhagavad Gita 14.16

कर्मणः सुकृतस्याहुः सात्त्विकं निर्मलं फलम्।रजसस्तु फलं दुःखमज्ञानं तमसः फलम्

They say that the fruit of good action is Sattvic and pure; indeed, the fruit of Rajas is pain, and the fruit of Tamas is ignorance.