Sanskrit
कर्मणः सुकृतस्याहुः सात्त्विकं निर्मलं फलम् । रजसस्तु फलं दुःखमज्ञानं तमसः फलम् ॥
karmaṇaḥ sukṛtasyāhuḥ sāttvikaṃ nirmalaṃ phalam rajasas tu phalaṃ duḥkham ajñānaṃ tamasaḥ phalam
Translation
It is said the fruit of a good action is harmonious and spotless; verily the fruit of Motion is pain, and the fruit of Inertia unwisdom.
Annie Besant · The Bhagavad-Gita, translated by Annie Besant (4th ed., 1922) — Wikisource · Public Domain
Explanation
The causal logic of the gunas extends beyond death into ordinary karma-phala: the fruit of sattvic action is pure and spotless, of rajasic action is pain, of tamasic action is unwisdom itself. It’s a tighter, more specific claim than the general teaching on non-attachment to results elsewhere in the Gita — here the quality of the guna behind an act determines the quality of what that act yields, independent of whether the actor is attached to the outcome or not.