Tafsir of Sad 38:64

(Indeed, that is surely the truth): That is, that which He narrated concerning them. (Is the disputation of the people of the Fire):

This is the predicate of an omitted subject, meaning: "It is the disputation." The sentence serves as an elaboration of "that." There is further confirmation in the progression from vagueness to clarification. Ibn Atiyyah said: "It is a substitute (badal) for 'the truth' (haqq), though the replaced term is not in the position of being dispensable." It is also said that it is a substitute for the position of the noun of Inna.

The intended meaning of "disputation" (takhāsum) is the exchange of speech. It is permissible to intend the literal meaning, for the statement of the leaders, "There is no welcome for them," and the statement of the followers, "Nay, [it is] you, there is no welcome for you," belong to the category of disputation. Thus, the entire negotiation is called "disputation" because it contains it.

It is said that this is apparent regarding the exchange of speech between the leaders and the followers. As for if the entire [preceding] discourse were attributed to the guardians [of Hell], it would not be so. If "There is no welcome" were attributed to the leaders and "This is a troop" were attributed to the guardians, it would be correct to consider it a metaphorical disputation. Ibn Abi Ablah read it as takhāsuman in the accusative case, making it a substitute for "that."

Al-Zamakhshari said: "It is an adjective for it." This was critiqued on the grounds that while it is permissible to describe a demonstrative noun with a non-derived word, it must be defined with 'al' (the definite article), as he mentioned in al-Mufassal without recording any disagreement on the matter. Thus, there is a contradiction between this and what the claim of it being an adjective necessitates, along with the separation that is forbidden or awkward.

The author of al-Kashf answered that analogy demands its permissibility, because a demonstrative noun requires something to lift its vagueness by indicating a specific entity, regardless of whether it possesses specificity to another essence or not. This degree does not exclude the noun from indicating the specific essence by which it is valid to be an adjective for a demonstrative noun. As for usage, it is countered by the principle of usage in adjectives. Just as the majority held it to be an adjective in expressions like "This man," despite the possibility of it being a substitute or an explanatory clause, Al-Zamakhshari held it to be an adjective despite the possibility of it being a substitute, because he focused on the meaning.

This does not contradict what is in al-Mufassal, because he mentioned that specifically in the chapter on the vocative, under the assumption that the demonstrative noun is not independent. Because the state of independence is less common, he did not address it. He clarified in its place that, specifically in the vocative, it is forbidden to describe a demonstrative noun if it is not independent with what is annexed to the definite article. Furthermore, he often contradicts himself between the two books, al-Kashshaf and al-Mufassal. The objection that "separation is required" is not damaging, for it is permissible, especially under the assumption that the demonstrative noun is independent.

Ibn al-Sumayqa' read takhāṣama as a past tense verb, with ahl (the people) in the nominative case, acting as its subject.