﴿ فَلَمَّا نَسُوا۟ مَا ذُكِّرُوا۟ بِهِۦ فَتَحْنَا عَلَيْهِمْ أَبْوَٰبَ كُلِّ شَىْءٍ حَتَّىٰٓ إِذَا فَرِحُوا۟ بِمَآ أُوتُوٓا۟ أَخَذْنَٰهُم بَغْتَةًۭ فَإِذَا هُم مُّبْلِسُونَ ﴾

“Then, when they had forgotten all that they had been told to take to heart, We threw open to them the gates of all [good] things until -even as they were rejoicing in what they had been granted - We suddenly took them to task: and lo! they were broken in spirit;”

So when they forgot when they neglected that whereof they were reminded that with which they were admonished and threatened in the way of misery and hardship; and they did not heed the admonition We opened read fatahnā or fattahnā to them the gates of all things in the way of graces in order to draw them on by degrees until when they rejoiced in what they were given a wanton rejoicing We seized them suddenly with chastisement and lo! they were confounded despairing of anything good.