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.