Abu Dawud Book 3, Hadith Number 1710.

Narated By AbuSa’id al-Khudri : Ali ibn AbuTalib found a dinar and he took it to Fatimah. She asked the Apostle of Allah (PBUH) about it. He said: This is Allah’s provision. Then the Apostle of Allah (PBUH) ate out of the food (bought with it), and Ali and Fatimah also ate out of that food. But afterwards a woman came crying out about the dinar. The Prophet (PBUH) said: Pay the dinar, Ali.