Bhagavad Gita Chapter 14.16
karmaṇaḥ sukṛtasyāhuḥ
sāttvikaḿ nirmalaḿ phalam
rajasas tu phalaḿ duḥkham
ajñānaḿ tamasaḥ phalam
Translation
The result of pious action is pure and is said to be in the mode of goodness. But action done in the mode of passion results in misery, and action performed in the mode of ignorance results in foolishness.