Sahih al-Bukhari, Hadith 2622 ⓘ
Narrated Ibn `Abbas: The Prophet said, "The bad example is not for us. He who takes back his present is like a dog that swallows back its vomit."
حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ الْمُبَارَكِ، حَدَّثَنَا عَبْدُ الْوَارِثِ، حَدَّثَنَا أَيُّوبُ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ قَالَ قَالَ النَّبِيُّ صلى الله عليه وسلم " لَيْسَ لَنَا مَثَلُ السَّوْءِ، الَّذِي يَعُودُ فِي هِبَتِهِ كَالْكَلْبِ يَرْجِعُ فِي قَيْئِهِ " .
also referenced under: Book 51, Hadith 54 (In-Book) & Volume 3, Book 47, Hadith 791 (USC-MSA)