الَّذِينَ كَذَّبُوا بِالْكِتَابِ وَبِمَا أَرْسَلْنَا بِهِ رُسُلَنَاThose who deny the Book, and that with which We sent Our Messengers,means, guidance and clear proof.فَسَوْفَ يَعْلَمُونَthey will come to know.This is a stern warning and clear threat from the Lord to these people.This is like the Ayah:وَيْلٌ يَوْمَيِذٍ لِّلْمُكَذِّبِينَWoe that Day to the deniers! (77:15