अफलाकाङ्क्षिभिर्यज्ञो विधिदृष्टो य इज्यते।यष्टव्यमेवेति मनः समाधाय स सात्त्विकः॥
aphalākāṅkṣibhir yajño vidhi-driṣṭo ya ijyateyaṣṭavyam eveti manaḥ samādhāya sa sāttvikaḥ
Word by word
The verse says
An offering made the way it should be made, by people wanting nothing back, with the mind settled on this simply being what is done - that one is clear.
In plain words
Three parts, and the third does the work.
Done properly. Done without wanting a result. And done with the mind settled on yaṣṭavyam eva - this is simply to be done.
Not because it will pay. Not even because it is noble. Because it is the thing that is done, and the question of why has stopped being asked.
Where you've felt this · at work
Ganesh has swept the same stretch of corridor for nineteen years, and he does the corner behind the pillar that nobody can see. There is no inspection and nobody has ever mentioned the corner. Ask him why and he looks at you oddly. He is not being virtuous about it. In his mind the corridor includes the corner, and that is the end of the matter.
Going deeper
Doing something because it is what is done, with the question of why settled, is the state being pointed at.
The phrase gets read as duty, which in English sounds grim and reluctant. That is not it. There is nothing heavy about the man who sweeps behind the pillar. The weight has gone out of the act because the arguing has gone out of it.
Chapter 2 said something similar about work done without clutching at the result: you have a claim on the doing and none on what follows. Here it has gone a step further. It is not only that the result has been released. The question itself has been put down.
That is worth wanting, and it is the opposite of effort. Every act you perform while still negotiating with yourself about it costs several times what it needs to. The settled mind in this verse is not disciplined. It has simply stopped arguing.