Tafsir of An-Naml 27:2

(A guidance and glad tidings) are in the position of the accusative case as a circumstantial qualifier (hal) from "the verses." The infinitive is placed in the position of the active agent for the sake of hyperbole, as if they are the very essence of guidance and glad tidings. The operative factor is the meaning of the indication, which is what the grammarians call a "semantic operative factor."

Abu al-Baqa’ permitted, regarding the reading in the nominative case for "a book," that the circumstantial qualifier could be derived from it. He then said: "It is weak to derive it from the genitive case, but it is permissible for it to be a circumstantial qualifier from the pronoun in 'clear' (mubin) according to both readings." Abu Hayyan permitted the accusative case based on its status as an infinitive—meaning: "they guide with a guidance and give glad tidings with glad tidings"—or the nominative case as a substitute for "the verses." The condition set by the Kufans—that in substituting an indefinite noun for a definite one, there must be two conditions: uniformity of wording and that the indefinite noun must be described, as in His saying, "Indeed, We will drag him by the forelock, a lying, sinning forelock"—is incorrect, as stated in Sharh al-Tashil, because of the testimony of auditory evidence to the contrary. Alternatively, it may be a predicate for "those," or a predicate for an elided subject, meaning: "They are a guidance and glad tidings."

(For the believers) It is possible that this is a qualifier for both the guidance and the glad tidings together. The meaning of the verses’ guidance for them, while they are already guided, is that it increases them in guidance, as the Almighty said: "As for those who believed, it increased them in faith, and they are rejoicing." As for the meaning of its giving them glad tidings, it is evident, for it gives them glad tidings of the mercy of Allah the Almighty, His approval, and gardens in which they have lasting bliss. This is what has been said. In the Shahabiyyah annotations, it is stated that "guidance" according to this possibility is either in the sense of "being guided" or is taken according to its apparent meaning. The specification of the believers is because they are the ones who benefit from it, even if its guidance is general. Considering "the believers" to mean "those who are becoming believers" is forced, just as interpreting their guidance as an increase in it is forced.

It is also possible that it is a qualifier for the glad tidings only, while the guidance remains general and in the sense of indication and direction—that is, a guidance for all those held accountable, and glad tidings for the believers.