Bhagavad Gita Chapter 18, Verse 12
अनिष्टमिष्टं मिश्रं च त्रिविधं कर्मणः फलम् | भवत्यत्यागिनां प्रेत्य न तु सन्न्यासिनां क्वचित् ||
aniṣṭam iṣṭaṁ miśraṁ ca trividhaṁ karmaṇaḥ phalam bhavaty atyāgināṁ pretya na tu sannyāsināṁ kvacit
The fruits of action are of three kinds—unfavorable, favorable, and mixed—for those attached to fruits, but not for renunciates, ever.
Krishna explains the relationship between action, fruits, and attachment. 'Aniṣṭam iṣṭaṁ miśraṁ ca trividhaṁ karmaṇaḥ phalam'—the fruits of action (karmaṇaḥ phalam) are of three kinds (trividham): unfavorable (aniṣṭam), favorable (iṣṭam), and mixed (miśram). 'Bhavaty atyāgināṁ pretya'—these fruits occur (bhavati) for those attached to fruits (atyāginām) after death (pretya), meaning they experience the consequences. 'Na tu sannyāsināṁ kvacit'—but not (na tu) for renunciates (sannyāsinām) at any time (kvacit). This is the key teaching: if you're attached to fruits, you experience three kinds of results—good, bad, mixed. But if you're a true renunciate (relinquishing fruits), you don't experience these consequences. This sets up the teaching about the three kinds of action according to gunas: sattvic, rajasic, tamasic.