Bhagavad Gita · Chapter 17: The Three Kinds of Faith

Bhagavad Gita 17.11

aphalākāṅkṣibhiryajño vidhidṛṣṭo ya ijyate | yaṣṭavyameveti manaḥ samādhāya sa sāttvikaḥ ||

A sacrifice that is offered as scripture directs, by those who want no reward, with the mind settled on the thought that it simply ought to be offered, is of clarity.

Modern context

A sattvic offering is made with no desire for reward, simply because it ought to be done. 'This should be offered' is the whole motive. This is a high standard. Most of our good actions carry some hope of return: thanks, recognition, a better future. To act simply because it is right is rare, but it is what makes an action clean.