Abu Dawud Book 30, Hadith Number 4237.

Chapter : Fitan and their predictions.

Narated By Abu Hurairah : The Prophet (PBUH) said: Woe to the Arabs because of the evil which has drawn near! He will escape who will restrain his hand.|Abu Dawud said Abdullah ibn Umar|

The Prophet (PBUH) said: The Muslims will soon be besieged up to Medina, so that their most distant frontier outpost will be Salah.