Surely Allah is not ashamed to set forth any parable-- (that of) a gnat or any thing above that; then as for those who believe, they know that it is the truth from their Lord, and as for those who disbelieve, they say: What is it that Allah means by this parable: He causes many to err by it and many He leads aright by it! but He does not cause to err by it (any) except the transgressors,

Allah’s Apostle said, “Not to wish to be the like except of two men. A man whom Allah has given the (knowledge of the) Qur’an and he recites it during the hours of night and day and the one who wishes says: If I were given the same as this (man) has been given, I would do what he does, and a man whom Allah has given wealth and he spends it in the just and right way, in which case the one who wishes says, ‘If I were given the same as he has been given, I would do what he does.’ ”