"The Messenger of Allah said: 'It is not permissible for anyone to give a gift then take it back, except from one's son.'" Tawus said: "When I was young I used to hear (the phrase), 'The one who goes back to his vomit,' but we did not realize that this was a similitude." He said: "The likeness of the one who does that is that of a dog which eats then vomits, then goes back to its vomit." (Using translation from Nasāʾī 3692)
قَالَ رَسُولُ اللهِ ﷺ «لَا يَحِلُّ لِأَحَدٍ أَنْ يَهَبَ هِبَةً ثُمَّ يَرْجِعَ فِيهَا إِلَّا مِنْ وَلَدِهِ» قَالَ طَاوُسٌ كُنْتُ أَسْمَعُ وَأَنَا صَغِيرٌ «عَائِدٌ فِي قَيْئِهِ» لَمْ أَكُنْ أَظُنُّ أَنَّهُ ضَرَبَ لَهُ مَثَلًا قَالَ «فَمَنْ فَعَلَ ذَلِكَ فَمَثَلُهُ كَمَثَلِ الْكَلْبِ يَأْكُلُ ثُمَّ يَقِيءُ ثُمَّ يَعُودُ فِي قَيْئِهِ»