It was narrated that Suwaid bin Ghafalah (ra) said: “I went out with Zaid bin Suhan (ra) and Salman bin Rabi'ah (ra), and when we were at `Udhaib, I found a whip. They said to me: 'Throw it away,' but I refused. When we came to Al-Madinah. I went to Ubayy bin Ka'b (ra) and told him about that. He said: 'You did the right thing. I found one hundred dinar that had been lost at the time of the Messenger of Allah (peace be upon him), and I asked him about it. He said, “Announce it for a year.” So I Announced it, and I did not find anyone who recognized it. He said: “Remember the features of its bag and strap, and how many it contains, then announce it for a year. If someone comes who describes it with those features, (give it to him), otherwise it is like your own property.”
(Sunan Ibn Majah 2506, Book 18, Hadith 5)