It is narrated from Sayyiduna Mu'awiyah bin Abi Sufyan (may Allah be pleased with him) that he said: I heard the Messenger of Allah (peace and blessings be upon him) say: "I am only a treasurer; it is Allah who gives. So whoever I give something to with a willing heart, it is blessed for him, and whoever I give something to because of the greed of his soul and his persistent asking, his example is that of one who eats but is never satisfied."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 16921