Expedition of Usama bin Zayd

The Expedition of Usama bin Zayd also known as the Army of Usama ibn Zaid to al-Balqa, took place in 11AH of the Islamic calendar, in May 632. Usama ibn Zayd was appointed as the commander of an expeditionary force which was to invade Palestine again (and attack Moab and Darum), on the orders of Muhammad. He set out with 3000 men on the same day Muhammad died, when he reached the destination he attacked the inhabitants, killing many, taking as many captives as he could.

Preparation
Muhammad invited Usama to a mosque and ordered him to act as the commander of an army that was to invade Palestine, and attack Takhum of al-Balqa (which was in Transjordan). Usama was the son of Zayd ibn Harithah, a slave that Muhammad freed, and a man that was very close to Muhammad. Zayd ibn Haritha was killed in the Battle of Mutah.

In addition to attacking Balqa, he was ordered raid Darum. Some weeks later, Muhammad fell ill, and from his seat (the Minbar) in the mosque, he ordered that Usama should lead the expeditionary force. Muhammad also rebuked those that claimed he did not merit such an honour, and rebuked those who claimed he was too young, while the best of Muhammad’s commanders were available.

He was specifically ordered by Muhammad to go to the place where his father and the Muslim commanders under him, had died and: “Attack the people of Ubna early in the morning”. He also ordered him to take women and children captive, instead of killing them.

Usama visited Muhammad before he went into battle. The next day he set out for his expedition and learnt Muhammad had died on 8 June 632. He was told by Abu Bakr to continue the expedition.

10 Rules of Abu Bakr
According to Tabari, before Usamah headed out, Abu Bakr advised Usamah with "10 things", which were like his rules of war. The tradition about the 10 "things" of Abu Bakr are also mentioned in the Sunni Hadith collection Muwatta Imam Malik The tradition mentioned many things, including leaving "monks" alone. Imam Shaffi (founder of the Shaffi school of thought) did not consider the tradition, about the 10 rules of Abu Bakr as authentic, but the same book which claimed he did not consider it authentic, also mentioned in another occasion that Shaffi considered it authentic (or partly authentic), and used it to justify killing monks only if they fought Muslims. But the same book explains that even if it was authentic, it does not mean that monks can not be killed, and claims that Abu Bakr's intention (according to Shaffi) was to only temporarily leave the monasteries alone. Shaffi concluded that "monks" are not included in his list of "non combatants". It is also worth mentioning that Abu Bakr left Usamah's Army against prophet's instructions in order to take over control of Muslim lands.

Invasion
Usama headed out with 3000 men, of which 1000 were cavalry soldiers. Abu Bakr accompanied Usama part of the way. Usama had also sent a spy, from which he learned that the inhabitants were still unaware of the imminent approach of the army.

Usama therefore hurried to Ubna, where he launched a surprise attack with the Muslims shouting their way cry: Ya Mansur amit (“O ye, Victory, Kill!”). At the same time, Usama rode his father’s horse, and killed the one who slew his father in the Battle of Mutah.

Hadith
The incident is mentioned in the Sahih Bukhari hadith collection: The Prophet appointed Usama as the commander of the troops (to be sent to Syria). The Muslims spoke about Usama (unfavorably ). The Prophet said, " I have been informed that you spoke about Usama. (Let it be known that ) he is the most beloved of all people to me." It is also mentioned in, , and others.

Historical sources
The event is also mentioned by the Muslim scholars Ibn Hisham, Waqidi and Tabari.

Tabari said about the event: In the year 11/632, during the month of Muharram,the Messenger of God ordered the people to undertake an expedition to Syria. He put Usamah, the son of his freed slave Zayd b. al-Harithah, incommand over them, ordering him to lead the cavalry into theterritory of al-Balqa' and al-Darum in the land of Pal-estine. The people got ready and the first emigrants wentforth all together with him. As the people were preparing for the expedition, the Prophet began to suffer from the sickness bywhich God took him to what honor and compassion He intended for him. [It took place] toward the end of Safar or at the beginningof Rabi` I [Tabari, Vol 9, Last Years of the Prophet, Pg 163-164].

It is also mentioned by Tabari, that Abu Bakr gave Usamah 10 rules, before he was sent forth and raided the inhabitants: Then (Abu Bakr) said, "Oh army, stop and I will order you [to do] ten [things]; learn them from me by heart. You shall not engage in treachery; you shall not act unfaithfully; you shall not engage in deception; you shall not indulge in mutilation; you shall kill neither a young child nor an old man nor a woman; you shall not fell palm trees or burnt them, you shall not cut down [any] fruit-bearing tree; you shall not slaughter a sheep or a cow or a camel except for food. You will pass people who occupy themselves in monks' cells; leave them alone, and leave alone what they busy themselves with. You will come to a people who will bring you vessels in which are varieties of food; if you eat anything from [those dishes], mention the name of God over them. You will meet a people who have shaven the middle of their head and have left around it [a ring of hair] like turbans; tap them lightly with the sword. Go ahead, in God's name; may God make you perish through wounds and plague!"

According to al-Sari — Shu'ayb — Sayf ; and according to 'Ubayd-allah — his uncle — Sayf — Hisham b. Urwah- his father: Abu Bakr went out to al-Jurf and followed Usamah and sent him off. He asked Usamah for 'Umar [b. al-Khattab], which he agreed to. He told Usamah "Do what the Prophet of God ordered you to do: Begin with the Quda'ah country, then go to Abil. Do not fall short in anything that the Messenger of God commanded, but do not hurry because of what not [yet] attained of his injunction.

So Usamah advanced quickly to Dhu al-Marwah and the valley and ended up doing what the Prophet had ordered him to do dispersing horsemen among the Quda'ah tribes and raiding Abil. He took captives and booty, and his completion [of the mission] was within forty days, excepting [the time of] his return.

[Tabari, Vol 10, The conquest of Arabia, Pg 16-17] Imam Shaffi (founder of the Shaffi school of thought) reportedly did not consider the tradition, about the 10 advice of Abu Bakr as authentic. The 10 advice of Abu Bakr is also mentioned in the Sunni Hadith collection Al-Muwatta. Abu Yusuf mentioned a counter tradition about the instructions of Abu Bakr.