Musannaf Ibn Abi Shayba 27:386

Abu Usama narrated to us, he said: Kahmas ibn al-Hasan narrated to us, from Abdullah ibn Shaqiq, he said: Harmi ibn al-Harith and Usama ibn Khuraym narrated to me—and they were companions in military expeditions—and they narrated a hadith to me, and neither of them knew that his companion had narrated it to me, from Murra al-Bahzi, he said: While we were with the Prophet of Allah, peace and blessings of Allah be upon him, one day on one of the paths of Medina, he said: "What will you do during a tribulation that rises in the regions of the earth as if it were the horns of a bull?" They said: "What should we do, O Messenger of Allah?" He said: "You must follow this one and his companions." He said: So I hurried until I turned toward the man and said: "This one, O Prophet of Allah?" He said: "This one." And behold, it was Uthman.