Tafsir of Al-Hajj 22:21

"And for them"—that is, for the disbelievers. That the pronoun refers to the guardians of Hell (the Zabaniyah) is far-fetched. The preposition lam (for) denotes desert, or it is used for the sake of irony against them. It is also said that it denotes purpose, and the speech implies an omitted genitive, meaning: "for their punishment." Others say it is in the sense of 'ala (upon), as in the saying of the Exalted: "And for them is the curse" (i.e., and upon them).

"Maces of iron"—the plural of miqma'ah. Its reality is that with which one is subdued, meaning: restrained with violence. In Majma' al-Bayan, it is described as a head-crusher, derived from qama'ahu qam'an (he subdued him), which means he deterred him. Ad-Dahhak and a group have interpreted it as hammers, and some as whips. In the Hadith: "If a single mace of these were placed upon the earth, then the two heavy ones (mankind and jinn) gathered together, they would not be able to lift it from the earth."