And indeed We gave Mûsâ (Moses) the Scripture, but dispute arose therein. And had it not been for a Word that went forth before from your Lord, (the torment would have overtaken them) and the matter would have been settled between them. But truly, they are in grave doubt thereto (i.e. about the Qur’ân). [Tafsir Al-Qurtubi].

Indeed, We had given Moses the Scripture, but differences arose regarding it. Had it not been for a prior decree from your Lord,¹ their differences would have been settled ˹at once˺. They are truly in alarming doubt about it.