Original: He is noted for his military prowess , commanding the forces of the Islamic prophet Muhammad and those of his immediate successors of the Rashidun Caliphate ; Abu Bakr and Umar ( Umar ibn al-Khattab ) .
Simplified: 17 Oct. 2006 [ ] He is famous for his military success , as he commanded the forces of Muhammad and of his immediate successors Abu Bakr and Umar ibn al-Khattab .