Word by Word Analysis

وَلَقَدْ صَدَّقَ عَلَيْهِمْ إِبْلِيسُ ظَنَّهُۥ فَٱتَّبَعُوهُ إِلَّا فَرِيقًا مِّنَ ٱلْمُؤْمِنِينَ 20

And Iblees had already confirmed through them his assumption, so they followed him, except for a party of believers.