Musannaf Ibn Abi Shayba 37:625

Al-Fadl ibn Dukayn narrated to us, from Fitr, from Abu Ishaq, from 'Umarah ibn 'Abd, who said: Hudhayfah said: "Beware of the doors of the rulers, for they are the stations of tribulations. Verily, tribulation is ambiguous when it approaches, and it becomes clear when it departs."