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,

And withhold yourself with those who call on their Lord morning and evening desiring His goodwill, and let not your eyes pass from them, desiring the beauties of this world's life; and do not follow him whose heart We have made unmindful to Our remembrance, and he follows his low desires and his case is one in which due bounds are exceeded.