It was narrated from 'Iyad bin Himar that the Messenger of Allah (ﷺ) said:
"Whoever finds lost property, let him ask one or two men of good character to witness it, then he should not alter it nor conceal it. If its owner comes along, then he has more right to it, otherwise it belongs to Allah (SWT), Who gives it to whomsoever He wills."
English reference: Vol. 3, Book 18, Hadith 2505
Arabic reference: Book 18, Hadith 2601