Musnad Ahmad 435:94

Yahya ibn Ishaq narrated to us, Ibn Lahi'ah informed us, from Ja'far ibn Rabi'ah, from Rabi'ah ibn Yazid, from Abdullah ibn 'Amir al-Yahsubi, who said: I heard Mu'awiyah ibn Abi Sufyan saying: I heard the Messenger of Allah (peace and blessings of Allah be upon him) saying: "I am only a treasurer, and it is Allah, the Mighty and Majestic, who gives. So, whoever I give a gift to with a good soul, it will be blessed for him. And whoever I give a gift to out of his greed of soul and his evil of asking, he is like the one who eats but is never satisfied."