" لَيْسَ لَنَا مَثَلُ السَّوْءِ الرَّاجِعُ فِي هِبَتِهِ كَالْكَلْبِ فِي قَيْئِهِ "
It was narrated that Ibn 'Abbas said: "The Messenger of Allah said: 'It does not befit us to leave bad examples. The one who takes back his gift is like a dog with its vomit.'"