Musnad Ahmad 27:927

Hassan ibn Musa and Husayn ibn Muhammad narrated to us, they said: Shayban narrated to us, from Yahya, from Abu Qilabah, from Salim ibn Abdullah ibn Umar, from Ibn Umar, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "A fire will emerge from Hadhramaut, or from the sea of Hadhramaut, before the Day of Resurrection, gathering the people." He said: We said: "O Messenger of Allah, what do you command us to do?" He said: "You must go to Ash-Sham."