The Messenger of Allah ﷺ said, "Whoever finds a lost item should call upon a just witness or two just witnesses, then he should not alter it nor conceal it. If its owner comes, he has the greater right to it. Otherwise, it is the property of Allah, which He gives to whomever He wills."
حدثنا أبو بكر بن أبي شيبة حدثنا عبد الوهاب الثقفي عن خالد الحذاء عن أبي العلاء عن مطرف
قال رسول الله ﷺ من وجد لقطة فليشهد ذا عدل أو ذوي عدل ثم لا يغيره ولا يكتم فإن جاء ربها فهو أحق بها وإلا فهو مال الله يؤتيه من يشاء
[Its chain of transmission is sahih] Abu Dawud transmitted it in the Book of Lost Property, Chapter on Announcing a Found Item, hadith no. 1709, from the hadith of Khalid Haddan, through this chain, and Ibn Hibban graded it sahih (Mawarid), hadith no. 1169.