Musnad Ahmad

Humaid bin Abdur Rahman says that once in Basra, Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrated this hadith to us: When Sayyiduna Umar (may Allah be pleased with him) was wounded in a murderous attack, I was the first to reach him. He said, "Remember three things from me, because I fear that by the time people arrive, I may not survive and people may not find me: No decision should be made regarding kalalah, no one should appoint a deputy or caliph over the people, and every slave of mine is free." People said to him, "O Leader of the Believers! Appoint someone as your successor." He replied, "Whichever course I choose, a person better than me has chosen it before me. So if I leave the matter of the people to themselves, the Prophet (peace and blessings be upon him) also did so, and if I appoint someone as my successor, a person better than me also appointed his successor, that is, Sayyiduna Abu Bakr (may Allah be pleased with him)." I said, "Glad tidings of Paradise to you! You had the honor of the companionship of the Prophet (peace and blessings be upon him) for a long time, then you were made the Leader of the Believers, and you proved your strength and fulfilled the trust." Sayyiduna Umar (may Allah be pleased with him) said, "The glad tidings of Paradise you have given me—by Allah! If I had the blessings and treasures of the world and all that is in it, I would give them as ransom for the terrifying events and scenes that will come before me before the real situation becomes clear. And as for the caliphate over the Muslims that you mentioned—by Allah! My wish is that I escape from it with nothing for or against me, neither any benefit nor any burden upon me. However, what you mentioned about the companionship of the Prophet (peace and blessings be upon him) is true."