Verily God hath purchased of the true believers their souls, and their substance, promising them the enjoyment of paradise; on condition that they fight for the cause of God: Whether they slay or be slain, the promise for the same is assuredly due by the law, and the gospel, and the Koran. And who performeth his contract more faithfully than God? Rejoice therefore in the contract which ye have made. This shall be great happiness.