Indeed, Allāh has purchased from the believers their lives and their properties [in exchange] for that they will have Paradise. They fight in the cause of Allāh, so they kill and are killed. [It is] a true promise [binding] upon Him in the Torah and the Gospel and the Qur’ān. And who is truer to his covenant than Allāh? So rejoice in your transaction which you have contracted. And it is that which is the great attainment.

Sahih International