Musnad Abu Ya'la al-Mawsili 42:100

Sufyan ibn Waki’ narrated to us, Muhammad ibn Bakr narrated to us, from Ibn Jurayj, Abu Bakr ibn Abdullah ibn Muhammad informed me that Sharik ibn Abdullah ibn Abi Namir narrated to him, from Ata’ ibn Yasar, from Abu Sa’id al-Khudri, from the Prophet (peace be upon him), that Ali brought him a dinar he had found in the market. He said, "Announce it for three [days]." He did not find anyone who recognized it. He returned to the Prophet (peace be upon him) and informed him. He said, "Eat it, or do as you wish with it." So he bought with three dirhams of it barley, and with three dirhams of it dates, and he bought with one dirham meat, and with one dirham oil, and one dirham remained with him. The exchange rate was eleven [dirhams] for a dinar. Then, after that, its owner came and described it. Ali said to him, "The Messenger of Allah (peace be upon him) commanded me to eat it." Its owner went to the Messenger of Allah (peace be upon him) and mentioned all of that to him. He said to Ali, "Return it to the man." He said, "I have already eaten it." The Prophet (peace be upon him) said, "If something comes to us, we will pay it to you."