With central Syria captured, the Muslims has given a decisive blow to the Byzantines. The communication between northern Syria and Palestine was now cut off. Abu Ubaidah decided to march to Fahl (Pella), which is about below sea level, and where a strong Byzantine garrison and survivors of Battle of Ajnadayn were present. The region was crucial because from here the Byzantine army could strike eastwards and cut the communications line with Arabia. Moreover, with this large garrison at the rear, Palestine could not be invaded.