I was not previously aware of that claim or of the verse but it does make sense. Thanks to Ria_Longhorn for the enlightenment. I searched for the verse. Here it is: Sahih International: Indeed, Allah has purchased from the believers their lives and their properties [in exchange] for that they will have Paradise. They fight in the cause of Allah , so they kill and are killed. [It is] a true promise [binding] upon Him in the Torah and the Gospel and the Qur'an. And who is truer to his covenant than Allah ? So rejoice in your transaction which you have contracted. And it is that which is the great attainment.