Musnad Ahmad 30:1654

Yahya ibn Ghaylan and Qutaybah ibn Sa'id narrated to us, they said: Rashdin ibn Sa'd narrated to us. Yahya ibn Ghaylan said in his narration: He said: Yunus ibn Yazid narrated to me, from Ibn Shihab, from Qabisah, from Abu Hurayrah, from the Messenger of Allah, may Allah bless him and grant him peace, that he said: "Black banners will emerge from Khurasan; nothing will turn them back until they are planted in Iliya."