Musnad Ahmad 31:772

Ya'qub narrated to us, Ibn Akhi Ibn Shihab narrated to us, from his paternal uncle Muhammad ibn Muslim, who said: Salim ibn Abdullah narrated to me, from Abdullah ibn Umar, that Abu Sa'id al-Khudri narrated to him a hadith similar to that from the Messenger of Allah, peace and blessings of Allah be upon him. Abdullah ibn Umar met him and said: "O Abu Sa'id, what is this that you are narrating from the Messenger of Allah, peace and blessings of Allah be upon him?" Abu Sa'id said: "I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: 'Gold for gold, like for like, and silver for silver, like for like.'"