﴿ ٱلَّذِينَ كَذَّبُوا۟ شُعَيْبًۭا كَأَن لَّمْ يَغْنَوْا۟ فِيهَا ۚ ٱلَّذِينَ كَذَّبُوا۟ شُعَيْبًۭا كَانُوا۟ هُمُ ٱلْخَٰسِرِينَ ﴾

“they who had given the lie to Shu'ayb - as though they had never lived there: they who had given the lie to Shu'ayb -it was they who were the losers!”

Those who denied Shu‘ayb alladhīna kadhdhabū Shu‘ayban this constitutes the subject of the sentence the predicate of which is introduced by the following ka-an ‘as if’ it is as if ka-an has been softened its subject omitted in other words understand it as ka-annahum they had never dwelt never had residence there in those dwelling-places of theirs; those who denied Shu‘ayb they were the losers the emphasis effected by the repetition of the relative clause alladhīna kadhdhabū Shu‘ayban ‘those who denied Shu‘ayb’ and what follows it is intended as a refutation of what they had said previously sc. ‘if you follow Shu‘ayb you shall indeed be losers’.