﴿ إِنَّهُۥ لَقَوْلٌۭ فَصْلٌۭ ﴾

“BEHOLD, this [divine writ] is indeed a word that between truth and falsehood,”

This is the reason why Allah swore: (Lo! this (Qur'an) is a conclusive word) a true exposition; it is also said this means: it is a judgement from Allah,