Sahih al-Bukhari 6975
Sahih al-Bukhari · Book 90: Tricks · (Tricks in) gift-giving and pre-emption
Narrated Ibn `Abbas:
حَدَّثَنَا أَبُو نُعَيْمٍ ، حَدَّثَنَا سُفْيَانُ ، عَنْ أَيُّوبَ السَّخْتِيَانِيِّ ، عَنْ عِكْرِمَةَ ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ قَالَ قَالَ النَّبِيُّ صلى الله عليه وسلم " الْعَائِدُ فِي هِبَتِهِ كَالْكَلْبِ يَعُودُ فِي قَيْئِهِ، لَيْسَ لَنَا مَثَلُ السَّوْءِ " .
The Prophet (ﷺ) said, "The one who takes back his gift is like a dog swallowing its own vomit, and we (believers) should not act according to this bad example."