Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: I heard the Messenger of Allah (peace and blessings be upon him) saying: "An evil likeness is not (fitting) for us: the likeness of the one who takes back his gift is that of a dog that returns to its vomit and eats it."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 10649