﴿ قُلْ هُوَ ٱلرَّحْمَٰنُ ءَامَنَّا بِهِۦ وَعَلَيْهِ تَوَكَّلْنَا ۖ فَسَتَعْلَمُونَ مَنْ هُوَ فِى ضَلَٰلٍۢ مُّبِينٍۢ ﴾

“Say: "He is the Most Gracious: we have attained to faith in Him, and in Him have we placed our trust; and in time you will come to know which of us was lost in manifest error."”

Say ‘He is the Compassionate One; we believe in Him and in Him we put our trust. And assuredly you will soon know sa-ta‘lamūna is also read sa-ya‘lamūna ‘they will know’ upon seeing the chastisement with your own eyes who is in manifest error’ is it us or yourselves or them?