Musannaf Ibn Abi Shayba 13:3177

Abu Bakr narrated to us, he said: Hafs narrated to us, from Sulayman ibn Abd Allah, he said: Al-Hasan said: Whoever acquires wealth from a man, or steals wealth from a man, and wishes to return it to him in a way that he does not know, and he delivers it to him, he said: There is no harm.