Ruling on one when he was young he found a wallet in the street and gave it to his paternal cousin
When I was almost fourteen years old, I found a wallet in the area where I live. It contained three thousand Riyals which I gave to my paternal cousin who lives with me in the same house. I turned to Allah (Exalted be He) in repentance of what I did. It must be noted that I knew the owner of the wallet, yet since I was not acquainted with him, I felt shy to give it to him. Moreover, the owner of the wallet lives in a remote area. What should I do? May Allah reward you with the best.
You must return the aforesaid wallet to its rightful owner unless he gives you permission to use it freely. If you feel shy to give it to him personally, you may send it by any means possible without their knowing who the finder was.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.
Date: Muharram 11, 1442 AH
Source: Fatawa Al-Lajnah Ad-Da'imah no. 18253-2
Shaykh Abdul-Aziz ibn Baz
Shaykh Salih Fawzan
Shaykh Abdul-Aziz Aal al-Shaykh
Shaykh Bakr Abu Zayd
Shaykh Abdullah ibn Ghudayyan