Sunan an-Nasa'i, Volume 4, Book 32, Hadith 3735 (DarusSalam) ⓘ

It was narrated from Hanzalah that he heard Tawus say: "Some of those who met the Prophet told us that he said: 'The likeness of the one who gives (something), then takes back his gift, is that of a dog which eats, then vomits, then eats its vomit.'"

أَخْبَرَنَا مُحَمَّدُ بْنُ حَاتِمِ بْنِ نُعَيْمٍ، قَالَ حَدَّثَنَا حِبَّانُ، أَنْبَأَنَا عَبْدُ اللَّهِ، عَنْ حَنْظَلَةَ، أَنَّهُ سَمِعَ طَاوُسًا، يَقُولُ أَخْبَرَنَا بَعْضُ، مَنْ أَدْرَكَ النَّبِيَّ صلى الله عليه وسلم أَنَّهُ قَالَ ‏ "‏ مَثَلُ الَّذِي يَهَبُ فَيَرْجِعُ فِي هِبَتِهِ كَمَثَلِ الْكَلْبِ يَأْكُلُ فَيَقِيءُ ثُمَّ يَأْكُلُ قَيْئَهُ ‏" ‏ ‏.‏