Wa laqad aatainaa Moosal Kitaaba fakhtulifa fee; wa lawlaa Kalimatun sabaqat mir Rabbika laqudiya bainahum; wa innahum lafee shakkim minhu mureeb
And We had already given Moses the Scripture, but it came under disagreement. And if not for a word [i.e., decree] that preceded from your Lord, it would have been concluded between them. And indeed they are, concerning it [i.e., the Quran], in disquieting doubt.
1 Mufti Taqi Usmani
And We gave Mūsā the book, then it was disputed (as well). But for a word that had already come from your Lord, the matter would have been decided between them. They are in confounding doubt about it.