Musnad Ahmad 962:183

Abu Abd al-Rahman said: I found in my father’s book in his own handwriting: Mahdi ibn Ja’far al-Ramli narrated to me, Damrah narrated to us, from al-Shaybani—and his name is Yahya ibn Abi ‘Amr—from ‘Amr ibn ‘Abd Allah al-Hadrami, from Abu Umamah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "A group of my Ummah will continue to be upon the religion, victorious over their enemy, prevailing. Those who oppose them will not harm them, except for the affliction that befalls them, until the command of Allah comes to them while they are in that state." They said: "O Messenger of Allah, and where are they?" He said: "In Bayt al-Maqdis (Jerusalem) and the surroundings of Bayt al-Maqdis."