´Narrated Abu Al-Ash'ath As-Sana'ani:` "Some people were delivering Khutbah in Ash-Sham, and among them were Companions of the Prophet (ﷺ). So the last of them, a man called Murrah bin Ka'b, stood, and he said: 'If it were not for a Hadith I heard from the Messenger of Allah (ﷺ), I would not have stood (to address you). He (ﷺ) mentioned the tribulations, and that they would be coming soon. Then a man who was concealed by a garment passed by. So he said: "This one will be upon guidance that day." So I went towards him, and it was 'Uthman bin 'Affan. I turned, facing him, and I said: "This one?" He said: "Yes."
Hadith Referenceسنن ترمذي / كتاب المناقب عن رسول الله صلى الله عليه وسلم / 3704