Abu Rafi' says: Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) was leaning against Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both), and with him were Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) and Sayyiduna Sa'id bin Zayd (may Allah be pleased with him). Sayyiduna Umar (may Allah be pleased with him) said: Know that I have not said anything about kalalah, and I am not appointing anyone as caliph after me. Whoever among the Arab captives is alive at the time of my death shall be counted free, from the wealth of Allah. Sayyiduna Sa'id bin Zayd (may Allah be pleased with him) said: If you were to point to one of the Muslims, the people would trust you in this. Sayyiduna Abu Bakr (may Allah be pleased with him) also did so, and the people trusted him as well. Sayyiduna Umar (may Allah be pleased with him) said: I have seen an unseemly eagerness among my companions. I am entrusting this matter to these six men, with whom the Prophet (peace and blessings be upon him) was pleased at the time of his passing. Then Sayyiduna Umar (may Allah be pleased with him) said: If one of two men were present now, I would appoint him as leader and have full confidence in him: Salim, the freed slave of Abu Hudhayfah, and Abu Ubaydah bin al-Jarrah.
Ahmad recorded it; its chain contains a narrator, Ali bin Zayd, whose hadith is hasan (good), though there is weakness in this narrator.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الوصايا / 7126
Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) says: When Sayyiduna Umar (may Allah be pleased with him) was wounded, I was the first to come to him. He said: Remember three things from me, for I fear that the people will not be able to reach me now: I have not given any ruling regarding kalalah, I have not appointed anyone as caliph over the people, and every slave of mine shall be counted free. Then the narrator mentioned the complete hadith.
Abu Ya'la recorded it in al-Kabir, and its narrators are thiqat (trustworthy). (It is stated this way in the Arabic text; perhaps the original wording should be:
Al-Tabarani recorded it in al-Mu'jam al-Kabir.)
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الوصايا / 7127