5.48 – And We have sent down to you the Book with the truth, confirming what was with him of the Book
After mentioning the Torah (vv. 43–44) and the Gospel (vv. 46–47), the Quran claims that “the Book with the truth” has now been “sent down” to the messenger. This verse says that the new book confirms the pre-Islamic scriptures. On the one hand, this claims a relationship of correspondence with the earlier scriptures. On the other hand, this verse raises the messenger’s recitation above all earlier scriptures as their judge (see also v. 49).
For an analysis of the Quran’s claim of confirmation, and a response, see 46.12. This verse also provides a positive parallel expression to “confirming”: “as a preserver of it (muhayminan ‘alayhi).” At the same time, the messenger is instructed to judge not by the earlier scriptures but by that which the Quran claims Allah “sent down” to him (also v. 49).