"[T]he jizyah was levied on the able-bodied males, in lieu of the military service they would have been called upon to perform had they been Musalmans; and it is very noticeable that when any Christian people served in the Muslim army, they were exempted from the payment of this tax. Such was the case with the tribe of al-Jurājima, a Christian tribe in the neighborhood of Antioch who made peace with the Muslims, promising to be their allies and fight on their side in battle, on condition that they should not be called upon to pay jizyah and should receive their proper share of the booty."