He said:"My Lord is the Best Knower of what you do."means, `Allah knows best about you, and if you deserve that, He will punish you therewith, and He will not treat you unjustly.'So this is what happened to them -- as they asked for -- an exact recompense.Allah says:فَكَذَّبُوهُ فَأَخَذَهُمْ عَذَابُ يَوْمِ الظُّلَّةِإِنَّهُ كَانَ عَذَابَ يَوْمٍ عَظِيمٍ