The punishment for one who recites the Quran but does not act in accordance with it
Question

I heard that one of the reasons why a person may be punished in the grave is a man who recites the Quran by night but does not act in accordance with it by day. Does this mean that the man never acted in accordance with the Quran at all, or that he only acted in accordance with some of it?
Praise be to Allah.It was narrated from Samurah ibn Jundub (may Allah be pleased with him) that the Prophet (blessings and peace of Allah be upon him) said regarding the dream he saw: “As for the man whose head was being smashed with a rock, he is one who studied the Quran but did not act upon it, and he went to sleep, neglecting the obligatory prayers.”
Narrated by al-Bukhari (1143); it is part of a lengthy hadith narrated in Sahih al-Bukhari (7047).
See the hadith of Samurah in its entirety in the answer to question no. 11110.
For more information, see the answer to question no. 46068.
What is meant by his head being smashed is that it was being crushed. End quote.
What the hadith refers to is not acting in accordance with the Quran. Ibn Battal said: What it means is that he does not memorize its words or act in accordance with its meanings. As for one who does not memorize its words but does act in accordance with its meanings, he is not included in this hadith, but it is narrated in the hadith that he will be resurrected on the Day of Resurrection with no argument to defend himself. End quote.
Ibn Battal: Sharh Sahih al-Bukhari (3/135, 9/564).
At-Tini said: The words “fa naama ‘anhu (he went to sleep and missed it)” mean: he turned away from it.
The preposition ‘an (away from) in this phrase is used in the same way as in the verse in which Allah, may He be exalted, says (interpretation of the meaning): {alladhina hum ‘an salatihum sahun [But] who are heedless of their prayer} [al-Ma‘un 107:5]. In other words, they are heedless in the sense of abandoning it and not paying attention to it. This is the action of the hypocrites and evildoers.
The phrase “he went to sleep and missed it” means: he does not recite it at night, and he does not reflect on what the Quran includes of commands that he should follow and prohibitions to which he should pay heed, like the hypocrites and evildoers. If this is how he is at night, then he will not act during the day on what it contains.
This interpretation is supported by what is mentioned in another report narrated by al-Bukhari: “As for the man whose head was being smashed with the rock, he is the one who studied the Quran but did not act upon it, and he went to sleep, neglecting the obligatory prayers.”
As for the one who sleeps without staying away from the Quran, due to some shortcoming or incapacity, he is not included in this warning. End quote.
At-Tibi: Sharh al-Mishkat (9/3009-3010).
To sum up: one of the causes of that punishment is sleeping and not reciting or reading Quran, because one does not want to act on it and is not interested in it.
As for the one who does not do something due to some shortcoming or incapacity, he is not included in this warning.
See also the answer to question no. 45325.
Secondly:
The believer should be keen to act in accordance with the Quran, because Allah says (interpretation of the meaning):
{Follow [O humankind] that which has been sent down to you from your Lord, and do not follow any close associates besides Him. Little is it that you pay heed!} [Al-A‘raf 7:3]
{Follow that which has been revealed to you from your Lord – there is no god worthy of worship except Him – and turn away from those who ascribe partners to Him}[Al-An‘am 6:106]
{So follow [O Muhammad] that which is revealed to you, and then be patient until Allah gives His judgement, for He is the best of judges} [Yunus 10:109].
In the hadith, an-Nawwas ibn Sam‘an al-Kilabi said: I heard the Prophet (blessings and peace of Allah be upon him) say: “The Quran will be brought on the Day of Resurrection, as will its people who used to act in accordance with it, led by Surat al-Baqarah and Al ‘Imran.” And the Messenger of Allah (blessings and peace of Allah be upon him) likened them to three things, which I did not forget afterwards. He said: “As if they are two clouds, or two black canopies, with light between them, or as if they are two flocks of birds in ranks, pleading on behalf of their companions.” Narrated by Muslim (805).
It was narrated that Ibn ‘Umar said: There was a time in the past when we learned issues of faith before Quran, and when a surah was revealed to Muhammad (blessings and peace of Allah be upon him), he would learn what it said was halal and haram, and what he should pay attention to in that surah just as you are taught the Quran. Then he said: I have seen men, one of whom learns the Quran and recites it from beginning to end, without learning what it enjoins and forbids, or in which verses he should pause and pay attention, and he reads it at speed, like spreading out dates to dry.
Narrated by al-Hakim in al-Mustadrak ‘ala as-Sahihayn (1/91, 101).
Al-Fudayl said: The Quran was revealed to be followed, but people regard reciting it as all that is required of them to do. It was said: How should we approach it? He said: You should regard what it says is halal as permissible and regard what it says is haram as prohibited; you should follow its commands and heed its prohibitions, and pause and reflect on its wonders. End quote.
Al-Khatib al-Baghdadi: Iqtida’ al-‘Ilm al-‘Amal (p. 76).
Ibn al-Qayyim said: Hence the people of the Quran are those who have knowledge of it and act in accordance with it, even if they do not memorize it by heart. As for the one who memorizes it but does not understand it or act on it, he is not one of its people, even if he is able to recite it perfectly. End quote from Zad al-Ma‘ad fi Hadi Khayr al-‘Ibad (1/402).
For more information on the texts which speak of this topic, please see: al-Khulasah fi Tadabbur al-Quran al-Karim by Dr. Khaalid as-Sabt (p. 68-72).
For more information, see the answer to question no. 93151.
And Allah knows best.