Sahih Muslim 1622
Sahih Muslim · Book 24: The Book of Gifts · The Prohibition Of Taking Back One's Charity After It Has Been Accepted, Except In The Case Of What A Father Gives To A Son Or Grandson
Abdullah b. Tawus reported on the authority of his father who reported from Ibn Abas (Allah be pleased with them) who reported from Allah's Messenger 'may peace be upon him) that he said:
وَحَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ ، أَخْبَرَنَا الْمَخْزُومِيُّ ، حَدَّثَنَا وُهَيْبٌ ، حَدَّثَنَا عَبْدُ اللَّهِ، بْنُ طَاوُسٍ عَنْ أَبِيهِ ، عَنِ ابْنِ عَبَّاسٍ ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " الْعَائِدُ فِي هِبَتِهِ كَالْكَلْبِ يَقِيءُ ثُمَّ يَعُودُ فِي قَيْئِهِ " .
One who gets back his gift is like a dog which vomits and then swallows that vomit.