From the Buddha’s teachings if you do kusala, you get the results of the kusala now. Where is it? And how do you show the result of kusala? It is in the quality of the mind; when we do kusala, the reflection of whether it is kusala is in the quality of the mind.
Now we are peaceful or we have insights because we develop sati, we develop samadhi, and it makes the mind feel well. There is a sense of wellness in the mind; there is growing confidence in the mind, so you know that kusala is received, is there.
Kusala or akusala refers to the quality of the mind – is it wholesome or unwholesome; that’s our measure.