(Allah) will say:"Like this Our Ayat came unto you, but you disregarded them, and so this Day, you will be neglected.Meaning, "When you turned away from the signs of Allah and dealt with them in the manner of one who does not remember them after they were conveyed to you. You neglected them, turned away from them and were heedless of them. Therefore, today We will treat you in the manner of one who has forgotten you."فَالْيَوْمَ نَنسَـهُمْ كَمَا نَسُواْ لِقَأءَ يَوْمِهِمْ هَـذَاSo this Day We shall forget them as they forgot their meeting of this Day. (7:51)For verily, the punishment will be a retribution that is based upon the type of deed that was done. However, forgetting the words of the Qur'an, while understanding its meaning and acting upon its legislation, is not included in the meaning of this specific threat. Yet, forgetting the words of the Qur'an has been warned against from a different aspect. It has been reported in the Sunnah that it is absolutely forbidden and there is a serious threat against one who forgets Qur'an (that he previously memorized)