Musnad Abu Ya'la al-Mawsili 110:140

Abdullah ibn Umar ibn Aban narrated to us, Abd al-Rahim ibn Sulayman narrated to us, al-Hasan ibn Ubayd Allah narrated to us, from Salim ibn Abi al-Ja'd, from Ibn Abbas, who said: Umar ibn al-Khattab saw a gold ring on my hand, so he took it and threw it away. He said: "I did not seek it, nor did he return it to me."