Hazrat Umar (may Allah be pleased with him) narrated that I gave a horse to a man to ride in the way of Allah, but that man spoiled the horse. So I wished to buy it back, and I also thought that he would sell it at a cheap price. Therefore, I asked the Messenger of Allah (peace and blessings of Allah be upon him) about this, and he said: Do not take back your charity, even if he gives it to you for one dirham, because the example of one who takes back what he has given in charity is like the one who vomits and then licks it up.

Hazrat Abdullah bin Umar (may Allah be pleased with them) narrated that Hazrat Umar bin Khattab (may Allah be pleased with him) had given a horse in the way of Allah for riding. Then he saw that the same horse was being sold. He wanted to buy his horse and asked the Messenger of Allah (peace and blessings be upon him) about it, so the Prophet (peace and blessings be upon him) said: Do not buy it, and do not take back your charity in this way.