Bhagavad Gita 14.16
They say the fruit of a meritorious action is spotless and pure; the outcome of passion is misery, and of ignorance, darkness.
कर्मणः सुकृतस्याहुः सात्त्विकं निर्मलं फलम्।रजसस्तु फलं दुःखमज्ञानं तमसः फलम्॥karmaṇaḥ sukṛtasyāhuḥ sāttvikaṃ nirmalaṃ phalam|rajasastu phalaṃ duḥkhamajñānaṃ tamasaḥ phalam||
English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).