عن ابن عباس رضي الله عنهما أن رسول الله صلى الله عليه وسلم قال‏:‏ ‏"‏الذي يعود في هبته كالكلب يرجع في قيئه‏"‏ ‏(‏‏(‏متفق عليه‏)‏‏)‏‏.‏ ‏(‏‏(‏وفي رواية‏:‏ ‏"‏مثل الذي يرجع في صدقته، كمثل الكلب يقيء، ثم يعود في قيئه فيأكله‏"‏‏.‏ وفي رواية‏:‏ ‏"‏العائد في هبته كالعائد في قيئه‏)‏‏)‏‏.‏

'Umar bin Al-Khattab (May Allah be pleased with him) said

I donated a horse in the way of Allah. Its new possessor did not treat it properly. I made my mind to buy it because I thought that he would sell it at a cheap price (now that it became weak and emaciated). I asked the Prophet (ﷺ) about it, whereupon he said, "Do not buy it and do not get back your charity, for one who gets back the charity is like a dog that eats its own vomit."[Al-Bukhari and Muslim]