Musnad Ahmad 27:89

Al-Walid narrated to us, Al-Awza'i narrated to us, that Yahya ibn Abi Kathir narrated to him, that Abu Qilabah narrated to him, from Salim ibn Abdullah, from Abdullah ibn Umar: He said, "I heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: 'A fire will emerge from Hadhramaut, or in Hadhramaut, and it will drive the people.' We said, 'O Messenger of Allah, what do you command us?' He said, 'You must go to Ash-Sham.'"