(10) باب هَلْ يَأْخُذُ اللُّقَطَةَ وَلاَ يَدَعُهَا تَضِيعُ، حَتَّى لاَ يَأْخُذَهَا مَنْ لاَ يَسْتَحِقُّ
Narrated Salama:
the above narration (Hadith 616) from Ubai bin Ka`b: adding, "I met the sub-narrator at Mecca later on, but he did not remember whether Ka`b had announced what he had found one year or three years."
Reference: Sahih al-Bukhari 2437
In-book reference: Book 45, Hadith 13
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 3, Book 42, Hadith 617