This is how that darkness within us finds its way out: First it agrees with everything good we do.
When we choose to meditate, it tells us,
“Yes! Meditate! That way you will become a great sage!”
When we choose to do a good deed, it says,
“Yes! You are so wonderful! Think what others will do in return for this!”
Slowly, slowly, it convinces us that any good we do requires its approval. And then, you’ve fallen into its trap.
Do good without reason. Then there are no traps.
Rabbi Yosef Yitzchak Schneersohn, Kuntreisim, vol. 1, 37a.
Maybe this issue or rewards has to do with home education:" if you do your bed and keep the room clean your will get X. " if you finish your meal you will get a desert" if you do your homework, you will get y." So the reward becomes a reinforcement for doing something good, not for itself but for the reward. The fragment is asking for spontaneity in our actions you see something going on try to act-even before thinking. It happened to me once and it was good lesson: I am driving, and I see a man fall in front on the sidewalk. stopped the car , parked, and went to help. I got out of the car without telling my children who were in the back. Yet, seconds later my son was out too, and between both of us help the man back on its feet. The whole incident was a lesson for my son without words, and no explanations after. A lesson by itself. Like Nike's ad "Just do it!"