Surah 22. Al-Hajj, Ayah 21

Lit., "for them will be grips (maqami) of iron". The noun miqma'ah - of which maqami is the plural - is derived from the verb qama'a, signifying "he curbed" or "restrained" or "held in subjection" (Lisan al-'Arab). Hence, the "iron grips" mentioned in the above verse denote the inescapability of the suffering in the hereafter to which "they who are bent on denying the truth" condemn themselves.

Read this with the next verse. There will be no escape from the final Punishment adjudged after the time of repentance is past.