A lot of time, when we give to others, we kind of expect (even if we don't say so) that they'll give us something in return or shower us with gratitude. At least, I know this is true for me. Sometimes, we can even slip into doing it in the hope of receiving those responses. But true generosity doesn't ask for any reward or thanks. It gives purely because giving is the right and good thing to do. For the sake of God alone.