Amatul Rahmân Omer:
And indeed We gave Moses the Scripture but (when the followers of the Scripture began tampering with it) differences arose about it. Had it not been a word (of promise) already made by your Lord the judgment (between them the disbelievers) would have been passed long ago (by the destruction of those who dispute about the prophecy). And they are in disquieting and grave doubt concerning this (- the fulfillment of the prophecy).
Surah Fussilat (They are Explained in Detail) Ayat 45