It is narrated from Hazrat Buraidah (may Allah be pleased with him) that I heard the Noble Prophet (peace and blessings be upon him) say: Soon after me, many armies will be dispatched. You should join the army going towards Khurasan and encamp in the city called "Marw," because it was built by Dhu al-Qarnayn and he prayed for blessings in it. Therefore, no harm will come to those who reside there.