According to later Muslim historians, Muhammad dispatched 3,000 of his troops to the area in Jumada al-awwal of the year 8 A.H. 629, for a quick expedition to attack and punish the tribes. The army was led by Zayd ibn Haritha; the second-in-command was Jafar ibn Abi Talib and the third was Abdullah ibn Rawahah.[5]
The leader of the Ghassanids is said to have gained word of the expedition and prepared his forces; he also sent to the Byzantines for aid. Muslim historians report that the Byzantine emperor Heraclius himself gathered an army and hurried to the aid of his Arab allies. Other sources say that the leader was the emperor's brother, Theodorus. The combined force of Roman soldiers and Arab allies is usually reported to be 100,000[3] to 200,000[5] according to Muslim sources.
When the Muslim troops arrived at the area to the east of Jordan and learnt of the size of the Byzantine army, they wanted to wait and send for reinforcements from Medina. Abdullah ibn Rawaha scolded them for their timidity, so they continued marching towards the waiting army.
[edit] The battle
The Muslims attacked the Byzantines at their camp by the village of Musharif and then withdrew towards Mu'tah. It was here that the two armies fought. During the battle, all three Muslim leaders fell one after the other as they took command of the force: first, Zayd ibn Haritha, then Jafar ibn Abi Talib, then Abdullah ibn Rawaha. Al-Bukhari reported that there were fifty stab wounds in Jafar's body, none of them in the back. After the death of the latter, the troops asked Thabit ibn Arkan to assume command; however, he declined and asked Khalid ibn al-Walid to take the lead.[5]
Khalid ibn Al-Walid reported that the fighting was so intense that he used nine swords which broke in the battle. Al-Walid, seeing that the situation was hopeless, prepared to withdraw. He continued to engage the Byzantines in skirmishes, but avoided pitched battle. One night he completely changed his troop dispositions and brought forth a rearguard that he had equipped with new banners; all this was intended to give the impression that reinforcements had arrived from Medina. He also ordered his cavalry to retreat behind a hill, hiding their movements, and then return, raising as much dust as they could. This also was intended to create the impression that further reinforcements were arriving. The Byzantines believed in the fictitious reinforcements and withdrew, thus allowing the Muslim force to safely retreat to Medina.
Muslim commentators on the battle have often praised the skirmishing tactics of Khalid ibn al-Walid, and regard him as one of the finest military commanders in history.[3][5]