Musannaf Ibn Abi Shayba 33:269

Abu Bakr narrated to us, he said: Abu Khalid al-Ahmar narrated to us, from Dawud, from Amir, from Ibn Abbas, who said: I entered upon Umar when he was stabbed. I said: "Receive glad tidings of Paradise, O Commander of the Faithful! You embraced Islam when the people disbelieved, and you struggled alongside the Messenger of Allah when the people abandoned him, and the Messenger of Allah passed away while he was pleased with you, and no two people disagreed regarding your caliphate, and you have been killed as a martyr." He said: "Repeat it to me." So I repeated it to him. He then said: "By the One besides Whom there is no god, if I possessed all that is on the earth of gold and silver, I would ransom myself with it from the terror of the place of emergence."