Sahih Muslim – Gifting in Islam

Umar b. Khattab reported: I donated a pedigree horse in the path of Allah. Its possesser made it languish. I thought that he would sell it at a cheap price. I asked Allah’s Menengsr (may peace be upon him) about it, whereupon he said: Don’t buy it and do not get back your charity, for one who gets back the charity is like a dog who swallows its vomit.