Musannaf Ibn Abi Shayba 13:1670

Abu Bakr narrated to us, he said: Abu Bakr ibn Ayyash narrated to us, from Abd al-Aziz ibn Rufay, he said: My father narrated to me, he said: I found ten dinars, so I came to Ibn Abbas and asked him about them. He said: "Announce them at the Stone (al-Hijr) for a year. If they are not identified, then give them away in charity. If their owner comes, then give him the choice between the reward or the compensation."