Sahih
أَخْبَرَنَا عَمْرُو بْنُ زُرَارَةَ، قَالَ حَدَّثَنَا إِسْمَاعِيلُ، عَنْ أَيُّوبَ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " لَيْسَ لَنَا مَثَلُ السَّوْءِ الْعَائِدُ فِي هِبَتِهِ كَالْكَلْبِ يَعُودُ 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 the dog which goes back to its vomit