Fussilat 41:45

وَلَقَدْ ءَاتَيْنَا مُوسَى ٱلْكِتَـٰبَ فَٱخْتُلِفَ فِيهِ ۗ وَلَوْلَا كَلِمَةٌ سَبَقَتْ مِن رَّبِّكَ لَقُضِىَ بَيْنَهُمْ ۚ وَإِنَّهُمْ لَفِى شَكٍّ مِّنْهُ مُرِيبٍ

Walaqad ātaynā mūsā l-kitāba fa-ukh'tulifa fīhi walawlā kalimatun sabaqat min rabbika laquḍiya baynahum wa-innahum lafī shakkin min'hu murībin

And We had already given Moses the Scripture, but it came under disagreement.¹ And if not for a word [i.e., decree]² that preceded from your Lord, it would have been concluded between them. And indeed they are, concerning it [i.e., the Qur’ān], in disquieting doubt.