The Messenger of Allah ﷺ said, "Whoever finds a lost item should call upon a trustworthy witness or two trustworthy witnesses, and should not conceal it or hide it away. If he finds its owner, let him return it to him. Otherwise, it is the wealth of Allah, which He gives to whomever He wills."
قال رسول الله ﷺ: من وجد لقطة فليشهد ذا عدل أو ذوي عدل، ولا يكتم، ولا يغيب، فإن وجد صاحبها فليردها عليه، وإلا فهو مال الله يؤتيه من يشاء.
Reported by Abu Dawud (1709), Ibn Majah (2505), Ahmad (17481), Ibn Hibban (4894), and Bayhaqi (6/187), all of them through the route of Khalid Haddan, from Abu Ala, from Mutarrif (meaning Ibn Abdullah), from Iyad bin Himar, who said and then narrated it. Abu Ala is Yazid bin Abdullah bin Shakhir. Mutarrif bin Abdullah is Ibn Shakhir, and this is a narration of the brother from his brother. Its chain of transmission is sahih.Their wordings are close to one another, except that after his saying, "let him return it to him," there is an addition, "for he has more right to it." This is how it appears in the narration of Ibn Majah, Ahmad, and others. It appears that this discrepancy goes back to Khalid Haddan, and both versions are sahih.The hadith indicates that whoever finds a lost item is not disliked for picking it up, and this is the view of the majority of scholars. When he picks it up, he must have witnesses testify to it, publicize it, and after a year he may take ownership of it. Some scholars, among them Imam Ahmad, disliked picking up a lost item, out of caution.