Musannaf Ibn Abi Shayba 36:530

Abu al-Ahwas narrated to us, from Abu Ishaq, from ‘Amr ibn Maymun, who said: When ‘Umar was stabbed, the people surged against one another until the sun was about to rise. Then a caller called out, "The prayer!" So they brought forward ‘Abd al-Rahman ibn ‘Awf, and he led them in prayer. He recited the two shortest surahs in the Qur’an: "Indeed, We have granted you, [O Muhammad], the Al-Kawthar" and "When the victory of Allah has come and the conquest." When morning came, the physician entered upon him while his wound was flowing with blood. He said, "Which drink is most beloved to you?" He replied, "Nabidh." So he called for nabidh and drank it, and it came out of his wound. The physician said to him, "Make your will, for I do not think you will be anything but dead today or tomorrow."