What is the response to one of the Christians who says that the noble verse, "Indeed, We have sent down the Dhikr (the Reminder), and indeed, We will be its Guardian," includes both the Torah and the Qur'an in God's preservation, arguing that the Torah was also described as a "Dhikr"?

The intended meaning of "the Dhikr" in Allah Almighty's saying: (Indeed, it is We who sent down the Dhikr and indeed, We will be its guardian) is the Holy Quran, by the consensus of scholars; this is supported by the context and by other verses that confirm that Allah guaranteed the preservation of the Holy Quran, while He entrusted the preservation of the Torah and the Gospel to the scholars of the People of the Book, who then corrupted and distorted them. The Quran is preserved in hearts and transmitted through continuous, successive narration (tawatur), unlike other books that are not preserved in the same manner.