Bhagwad Gita
Chapter 17, Verse 17
श्रद्धया परया तप्तं तपस्तत्ित्रविधं नरैः।अफलाकाङ्क्षिभिर्युक्तैः सात्त्विकं परिचक्षते।।17.17।।
This threefold austerity, practiced by men whose aim is not to benefit themselves materially but to please the Supreme, is of the nature of goodness.