Musannaf Ibn Abi Shayba 33:987

Yahya ibn Yaman narrated to us, from Malik ibn Mughawwal, from Muhammad ibn Jahada, who said: A *barhdhun* (pack horse/mule) passed by al-Hasan, moving with a smooth, ambling gait. He said: "Oh, I have indeed known that when the Hour approaches, it approaches with distress."