{ Indeed Allah has bought, from the Believers, their lives and their wealth, so that Jannah may be theirs; they fight in the cause of Allah, and kill and are killed, a promise of truth on Him in the Torah, the Injil, and the Qur’an. And who is more faithful to His covenant than Allah? So rejoice over the deal that you have pledged to; this is the great victory } Al-tawba 111

{ So that Jannah may be theirs } ; Sa’id ibn Jubair said: He means Jannah, and the way of speaking here is figurative; the meaning is that Allah Most High has ordered them to wage jihad with their lives and with their wealth, in order that He may reward them with Jannah. He expresses this as a purchase because in it there is compensation as well as one who is compensated, and so this is its meaning; because a true purchase involves something the buyer does not possess.