Al-Anbiya: 50

(And this is a blessed reminder)

(And this) — meaning the Noble Qur’an; it is referred to by "this" to signal the ease of grasping it and the clarity of its matter. It is also said: it is due to the proximity of its time. (A reminder) — by which he who remembers may remember. It is described with this latter description, just as the Torah was, due to the appropriateness of the context and its consistency with what passed at the beginning of this noble Surah, while encompassing everything that preceded in its description. (Blessed) — meaning: possessing much good and abundant benefit; and we have received from its blessings, to Allah belongs all praise, what we have received.

(That We have sent down) — this is either a second adjective for "reminder" or a second predicate for "this"; in both cases, it contains an exaltation of the affair of the Noble Qur’an.

(Are you, then, deniers of it?)

This is a denial of their denial, after it has become apparent that its status is like the Torah. It is as if it were said: "After you have known that its status is the status of the Torah, are you deniers that it is revealed from Us?" For that, after observing the state of the Torah, is something that has no justification at all. The prepositional phrase is placed first to observe the rhythm of the verse endings, or for the purpose of restriction, because they acknowledge other than it from what is in the hands of the People of the Book.