Musannaf Ibn Abi Shayba 16:944

Abu Bakr narrated to us, he said: Ma'n ibn 'Isa narrated to us, from Hisham ibn Sa'd, from Ja'far ibn Nawfal, he said: I saw Ibn 'Abbas and his ring was on his right hand, and I do not think but that he mentioned that the Prophet, may Allah bless him and grant him peace, used to wear it likewise.