Tafsir of Al-Muddathir 74:36

(A warner to mankind): It is said that this is a specification (tamyiz) for “one of the greatest” (al-kubar), on the basis that nadhiran is an infinitive (masdar) meaning indharan (warning), similar to al-nakir meaning al-inkar (denial). The meaning, according to what you have heard from al-Zamakhshari, is that it [the Fire] is one of the greatest calamities as a warning. It is like when you say, "She is one of the women in terms of chastity."

Al-Farra’ said it is an infinitive in the accusative case by the implicit verb, meaning: "It warns." Many others held that it is an active participle (ism fa'il) meaning "warning" (mundhirah). Al-Zajjaj said it is a state (hal) of the pronoun in “innaha” (that it is), and it contains the phenomenon of the state being derived from the name of inna. It is also said that it is a state of the pronoun in “li-ihda” (for one of). Abu al-Baqa’ chose for it to be a state of what the sentence signifies; the estimation being: "It became great or significant as a warner." According to Abu Hayyan, this is a position in which there is no harm. These aspects are also permissible if it is considered an infinitive, by interpreting it as an adjective.

Al-Nahhas said the ta' marbuta (the letter ha) was omitted from nadhiran—even if it refers to the Fire—in the sense of attribution (nisbah), meaning "possessing warning." It may also be said regarding the non-attachment of the ha therein that it is similar to what is said regarding its non-attachment in the words of the Almighty: "Indeed, the mercy of Allah is near (qarib) to the doers of good" (al-A'raf: 56).

Abu Razin said that the meaning of "warner" here is Allah—the Exalted—and it is therefore in the accusative case due to an implicit verb, meaning: "Call upon a warner," or something similar. Ibn Zayd said the meaning is the Prophet (may the blessings of Allah be upon him). It is said that it is also in the accusative case due to an implicit verb, meaning: "Call," "convey," or "proclaim." This is as you can see [questionable].

If it were made a state (hal) of the hidden pronoun in the verb [of the command] qum (arise), it would be more appropriate. Likewise, if it were made a vocative, the speech would be analogous to your saying, "The matter is such-and-such, O so-and-so." It is also said that, according to this, it is a state of the pronoun in qum (arise) at the beginning of the Surah, but this disrupts the majestic order, and for this reason, it is said to be among the innovations of interpretations.

Ubayy and Ibn Abi 'Ablah read nadhirun (with a nominative damma) as a predicate after a predicate, or as a predicate for an omitted subject—meaning: "It is a warner," according to what is relied upon: that it is a description of the Fire. As for the position that it is a description of Allah—the Exalted—or the Messenger (peace and blessings be upon him), then it is a predicate for an omitted subject and nothing else; meaning: "He is a warner."