‘Iyad b. Himar reported God’s Messenger as saying, “He who finds Something should call one or two trusty people as witness and not conceal it or cover it up; then if he finds its owner he should return it to him, otherwise it is God’s property which he gives to whom He will.”
Al-Jarud reported God’s Messenger as saying, “A Muslim’s lost property is a cause of the flame of hell*.”
* i.e. when the finder, wishing to keep the article, does not make public the fact that he has found it.
Abu Sa'id al-Khudri said that ‘Ali b. Abu Talib found a dinar and after taking it to Fatima asked God’s Messenger about it. He replied that this was God’s provision, and God’s Messenger, ‘Ali and Fatima ate food which was bought with it. But afterwards a woman came crying out about the dinar and God’s Messenger said, “Pay the dinar, ‘Ali.”