وَلَقَد آتَينا موسَى الكِتابَ فَاختُلِفَ فيهِ ۗ وَلَولا كَلِمَةٌ سَبَقَت مِن رَبِّكَ لَقُضِيَ بَينَهُم ۚ وَإِنَّهُم لَفي شَكٍّ مِنهُ مُريبٍ

And We had already given Moses the Scripture, but it came under disagreement. And if not for a word that preceded from your Lord, it would have been concluded between them. And indeed they are, concerning the Qur'an, in disquieting doubt.