("Depart you to that which you used to deny! Depart you to a shadow in three columns, neither shady nor of any use against the fierce flame of the Fire. '' Verily, it throws sparks like fortresses, as if they were yellow camels or bundles of ropes. Woe that Day to the deniers.)(77:29-34). Allah said in this Ayah,
وَظِلٍّ مِّن يَحْمُومٍ
(And a shadow from Yahmum,) meaning, black smoke,
لاَّ بَارِدٍ وَلاَ كَرِيمٍ
(Neither Barid nor Karim,) means, it neither brings soft, cool breeze nor appears clear. Al-Hasan and Qatadah commented on Allah's statement,
(nor Karim) "Its sight is not pleasant.'' Ad-Dahhak said, "Every drink that is not fresh, is not Karim (pleasant). Then, Allah the Exalted stated that they deserve this end,
إِنَّهُمْ كَانُواْ قَبْلَ ذَلِكَ مُتْرَفِينَ
(Verily, before that, they indulged in luxury,) meaning, in the life of the world, they were enjoying life's pleasures and satisfying their lusts, all the while ignoring what the Messengers brought to them,
(And were persisting), means, they persisted and did not intend to repent,
عَلَى الْحِنثِ الْعَظِيمِ
(in great sin.) in disbelief in Allah and claiming that the idols and rivals were gods besides Allah. It means idolatry, according to Ibn `Abbas. This is also the meaning reported from Mujahid, `Ikrimah, Ad-Dahhak, Qatadah, As-Suddi and others. Allah said,
(And they used to say: "When we die and become dust and bones, shall we then indeed be resurrected And also our forefathers'') They said this while denying and rejecting the idea that resurrection will ever occur. Allah the Exalted said,
(Say: "(Yes) verily, those of old, and those of later times. All will surely be gathered together for appointed meeting of a known Day.'') meaning, `Say, O Muhammad, that the earlier and latter generations of the Children of Adam will be gathered for the Day of Resurrection and none of them will be left out. Allah the Exalted said:
(That is a Day whereon mankind will be gathered together, and that is a Day when all will be present. And We delay it only for a term fixed. On the Day when it comes, no person shall speak except by His leave. Some among them will be wretched and (others) blessed.)(11:103-105) He also said here,
لَمَجْمُوعُونَ إِلَى مِيقَـتِ يَوْمٍ مَّعْلُومٍ
(All will surely be gathered together for appointed meeting of a known Day.) because that time is precisely designated and will not come late, early, nor increase or decrease. Allah said,
(Then verily, --- you the erring-ones, the deniers! You verily, will eat of the trees of Zaqqum. Then you will fill your bellies therewith.) indicating that they will be seized and made to eat from the Zaqqum tree until their stomachs become full,
(And drink the Hamim on top of it. And you will drink (that) like Al-Him!) Hamim is boiling water, while Al-Him means thirsty camels, according to Ibn `Abbas, Mujahid, Sa`id bin Jubayr and `Ikrimah. As-Suddi said "Al-Him is a disease that strikes camels, causing them to feel thirst, and they drink until they die.'' Therefore, he said, the people of Hell, will never quench their thirst from drinking Hamim. Allah, the Exalted, said,
هَـذَا نُزُلُهُمْ يَوْمَ الدِّينِ
(That will be their entertainment on the Day of Recompense!) `this, what We have described, is their entertainment with their Lord on the Day of their Reckoning.' Allah the Exalted said in the case of the believers,
(Verily, those who believe and do righteous good deeds, shall have the Gardens of Al-Firdaws (Paradise) for their entertainment.)(18:107), i.e., hospitality and honor.
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
That is, "Their prosperity had an adverse effect on them. Instead of being grateful to Allah Almighty, they had become deniers of His blessings. Lost in pleasure-seeking they had forgotten God and persisted in heinous sinning. "Heinous sinning" includes disbelief, polytheism and atheism as well as every grave sin of morality and conduct."
For the explanation of zaqqum, sec E.N. 34 of As-Saaffat.