Bhagavad Gita Chapter 18, Verse 36
सुखं त्विदानीं त्रिविधं शृणु मे भरतर्षभ | अभ्यासाद्रमते यत्र दुःखान्तं च निगच्छति ||
sukhaṁ tv idānīṁ trividhaṁ śṛṇu me bharatarṣabha abhyāsād ramate yatra duḥkhāntaṁ ca nigacchati
O best of the Bharatas, hear from Me now about the three kinds of happiness, by practice of which one rejoices and reaches the end of suffering.
Krishna introduces the teaching about the three kinds of happiness. 'Sukhaṁ tv idānīṁ trividhaṁ śṛṇu me bharatarṣabha'—hear (śṛṇu) from Me (me) now (idānīm) about the three kinds (trividham) of happiness (sukham), O best of the Bharatas (bharatarṣabha). 'Abhyāsād ramate yatra duḥkhāntaṁ ca nigacchati'—by practice of which (yatra abhyāsāt) one rejoices (ramate) and reaches (nigacchati) the end of suffering (duḥkhāntam). This sets up the detailed teaching about how happiness is classified according to the three gunas: sattvic, rajasic, and tamasic. Understanding this helps you recognize the quality of your happiness and how it leads to or away from the end of suffering. The teaching will show that sattvic happiness, though initially difficult, leads to the end of suffering, while rajasic and tamasic happiness create more suffering.