When Munkar and Nakir interrogate the recently deceased and he fails to respond, do they subject him to continuous punishment until the Day of Reckoning or simply for a predetermined period?
The question is inaccurately phrased and perhaps the petitioner desires to say instead of the statement “he fails to respond” that “he does not confess to the mission of Muhammad” as there is no mention in any of the hadiths (prophetic traditions) of anyone interrogated who refuses to answer. The narrated responses are either: “He is Muhammad, the one who delivered the truth to us” and other similar responses bearing the same meaning, or: “I do not know; I heard others saying things and simply imitated them” and other similar-meaning expressions. Perhaps the petitioner intends by his statement “he fails to respond” that “he fails to respond with the correct answer”.
Likewise the statement “they subject him to continuous punishment” is incorrect as no hadith (prophetic tradition) attributes the punishment of one in the grave specifically to Munkar and Nakir and the correct expression would have been to say “Is he punished…?” in the passive voice, instead of attributing it to anyone in specific.
The answer is that the punishment of [both] the disbeliever (kafir) and the hypocrite (munafiq) embroiled in hypocrisy to the degree that it renders him a disbeliever (nifaq kufr) is endless and continues forever as stated in numerous hadiths.
In some of the chains of narration of the lengthy hadith narrated by al-Bara’ ibn `Azib (which is transmitted by Ahmad and judged sahih (authentic) by Abu ‘Awanah in the Chapter on the Manner of Interrogation in the Grave (Sifat al-Musa’alah fi ’l-Qabr), [the Prophet ﷺ] states at the end “…then a rift is opened into Hell and its smoke and misery allowed to blow into his grave till the Day of Judgment…” Another chain has it as “…then a deaf, dumb and blind creature is appointed over him. This being will hold an iron rod so heavy that were a mountain struck with it, it would be rendered into dust. He will strike the deceased a single blow [which will atomize his entire body] causing him to become dust. Immediately thereafter he will be regenerated and the process repeated [endlessly]…”
In the narration of Abu Hurayrah (transmitted by Ahmad, Tirmidhi and also ranked sound by Ibn Hibban in The Manner of Interrogation (Sifat al-Musa’alah)), the Prophet ﷺ states “…the earth will be commanded: Come together! Whereupon [the sides of his grave] will crush him till his ribs pierce each other and interlace, and the walls join with each other. In this state of punishment, he will remain till Allah resurrects him from the grave on the Day of Judgment.”
In the narration of Abu Sa‘id which is transmitted by Tirmidhi, the Prophet ﷺ states “…it will come together till his ribs interlace. Thereafter 70 serpents, with venom so deadly were one to blow on the earth all life would end, will be set upon him. They will bite him and rip his flesh [with their teeth] until the time arrives for him to be resurrected to account (hisab) for his deeds.”
The reconciliation between these variant hadiths [prophetic traditions] is to say that the punishment of kuffar (disbelievers) in the grave will be various. Ibn Abi ’l-Dunya transmits in his Al-Qubur [The Graves] the warning of Sha‘bi: “A man was walking past a grave[yard] when he saw a dead person clambering out of a grave. Immediately another appeared who struck him such a severe blow that he disappeared back into the grave. The man hurriedly left the graveyard and informed the Messenger of Allah ﷺ who remarked simply: “That was Abu Jahl ibn Hisham who will be punished till the Day of Judgment.”
[From the Fatawa of Ibn Hajar al-‘Asqalani on Islamic Creed, with slight changes made by the editors]