as for belief it is to believe in god almighty in his saying .. and to believe in the messenger may god bless him and grant him peace in what he came with. as for the proof it is to know the reason for the corruption of his analogy.. that his saying the world is cash and the hereafter is credit is a correct premise. as for his saying cash is better than credit it is a place of deception.. and the matter is not
أما التصديق فهو أن يصدق الله تعالى فى قوله .. وتصديق الرسول صلى الله عليه وسلم فيما جاء به..وأما البرهان وهو أن يعرف وجه فساد قياسه.. أن قوله الدنيا نقد والآخرة نسيئة مقدمة صحيحة وأما قوله النقد خير من النسيئة. فهو محل التلبيس.. وليس الأمر