Sahih Muslim Book 18, Hadith Number 4275.

Chapter : Stray thing found by anyone.

Zaid b. Khalid al-Juhani reported. There came to Allah’s Messenger (may peace be upon him) a person, the rest of the hadith is the same but with the variation (of these words): His face became red, his forehead too, and he felt annoyed; and made an addition after the words: He should make announcement of that for a year, and if its owner does not turn up, then it is a trust with you.