Allah mentioned the claim of the Jews, that the Fire will only touch them for a few days, and then they will be saved from it. Allah refuted this claim by saying,
﴿ قُلۡ أَتَّخَذۡتُمۡ عِندَ ٱللَّهِ عَهۡدً۬ا ﴾
(Say (O Muhammad to them): "Have you taken a covenant from Allah'). Hence, the Ayah proclaims, `if you had a promise from Allah for that, then Allah will never break His promise. However, such promise never existed. Rather, what you say, about Allah, you have no knowledge of and you thus utter a lie about Him.' Al-`Awfi said that Ibn `Abbas said about the Ayah,
﴿ وَقَالُواْ لَن تَمَسَّنَا ٱلنَّارُ إِلَّآ أَيَّامً۬ا مَّعۡدُودَةً۬ۚ ﴾
(And they (Jews) say, "The Fire shall not touch us but for a few numbered days.''). "The Jews said, `The Fire will only touch us for forty days.''' Others added that this was the period during which the Jews worshipped the calf.
Also, Al-Hafiz Abu Bakr bin Marduwyah reported Abu Hurayrah saying,
لَمَّا فُتِحَتْ خَيْبَرُ أُهْدِيَتْ لِرَسُولِ اللهِ صلى الله عليه وسلّم شَاةٌ فِيهَا سُمٌّ، فَقَالَ رَسُولُ اللهِ صلى الله عليه وسلّم:
«اجْمَعُوا لِي مَنْ كَانَ مِنَ الْيَهُودِ ههُنَا»
فَقَالَ لَهُمْ رَسُولُ اللهِ صلى الله عليه وسلّم:
«مَنْ أَبُوكُم؟»
قَالُوا: فُلَانٌ قَالَ:
«كَذَبْتُمْ بَلْ أَبُوكُمْ فُلَان»
فَقَالُوا: صَدَقْتَ وَبَرَرْتَ ثُمَّ قَالَ لَهُمْ:
«هَلْ أَنْتُمْ صَادِقِيَّ عَنْ شَيءٍ إِنْ سَأَلْتُكُمْ عَنْه؟»
قَالُوا: نَعَمْ يَا أَبَا الْقَاسِمِ وَإِنْ كَذَبْنَاكَ عَرَفْتَ كَذْبَنَا كَمَا عَرَفْتَهُ فِي أَبِينَا فَقَالَ لَهُمْ رَسُولُ اللهِ صلى الله عليه وسلّم:
«مَنْ أَهْلُ النَّارِ؟»
فَقَالُوا: نَكُونُ فِيهَا يَسِيرًا ثُمَّ تَخْلُفُونَا فِيهَا فَقَالَ لَهُم رَسُولُ اللهِ صلى الله عليه وسلّم:
«اخْسَئُوا وَاللهِ لَا نَخْلُفُكُمْ فِيهَا أَبَدًا»
ثُمَّ قَالَ لَهُمْ رَسُولُ اللهِ صلى الله عليه وسلّم:
«هَلْ أَنْتُمْ صَادِقِيَّ عَنْ شَيءٍ إِنْ سَأَلْتُكُمْ عَنْهُ؟»
قَالُوا: نَعَمْ يَا أَبَا الْقَاسِمِ، قَالَ:
«هَلْ جَعَلْتُمْ فِي هذِهِ الشَّاةِ سُمًّا؟»
فَقَالُوا: نَعَمْ قَالَ:
«فَمَا حَمَلَكُم عَلى ذلِكَ؟»
فَقَالُوا: أَرَدْنَا إِنْ كُنْتَ كَاذِبًا أَنْ نَسْتَرِيحَ مِنْكَ وَإِنْ كُنْتَ نَبِيًّا لَمْ يَضُرَّكَ.
(When Khaybar was conquered, a roasted poisoned sheep was presented to the Prophet as a gift (by the Jews). The Messenger of Allah ordered, `Assemble before me all the Jews who were here.' The Jews were summoned and the Prophet said (to them), `Who is your father' They replied, `So-and-so.' He said, `You have lied; your father is so-and-so.' They said, `You have uttered the truth.' He said, `Will you now tell me the truth, if I ask you about something' They replied, `Yes, O Abul-Qasim; and if we should tell a lie, you will know our lie as you have about our fathers.' On that he asked, `Who are the people of the (Hell) Fire' They said, `We shall remain in the (Hell) Fire for a short period, and after that you will replace us in it.' The Prophet said, `May you be cursed and humiliated in it! By Allah, we shall never replace you in it.' Then he asked, `Will you tell me the truth if I ask you a question' They said, `Yes, O Abul-Qasim.' He asked, `Have you poisoned this sheep' They said, `Yes.' He asked, `What made you do so' They said, `We wanted to know if you were a liar, in which case we would get rid of you, and if you were a Prophet then the poison would not harm you.') Imam Ahmad, Al-Bukhari and An-Nasa'i recorded similarly.
﴿ بَلَىٰ مَن كَسَبَ سَيِّئَةً۬ وَأَحَـٰطَتۡ بِهِۦ خَطِيٓـَٔتُهُ ۥ فَأُوْلَـٰٓٮِٕكَ أَصۡحَـٰبُ ٱلنَّارِۖ هُمۡ فِيهَا خَـٰلِدُونَ • وَٱلَّذِينَ ءَامَنُواْ وَعَمِلُواْ ٱلصَّـٰلِحَـٰتِ أُوْلَـٰٓٮِٕكَ أَصۡحَـٰبُ ٱلۡجَنَّةِۖ هُمۡ فِيہَا خَـٰلِدُونَ ﴾
(81. Yes! Whosoever earns evil and his sin has surrounded him, they are dwellers of the Fire (i.e. Hell); they will dwell therein forever). (82. And those who believe and do righteous good deeds, they are dwellers of Paradise, they will dwell therein forever.)
Allah says, the matter is not as you have wished and hoped it to be. Rather, whoever does an evil deed and abides purposefully in his error, coming on the Day of Resurrection with no good deeds, only evil deeds, then he will be among the people of the Fire.
﴿ وَٱلَّذِينَ ءَامَنُواْ وَعَمِلُواْ ٱلصَّـٰلِحَـٰتِ ﴾
(And those who believe and do righteous good deeds) meaning, "They believe in Allah and His Messenger and perform the good deeds that conform with the Islamic Law. They shall be among the people of Paradise.'' Allah said in a similar statement,
﴿ لَّيۡسَ بِأَمَانِيِّكُمۡ وَلَآ أَمَانِىِّ أَهۡلِ ٱلۡڪِتَـٰبِۗ مَن يَعۡمَلۡ سُوٓءً۬ا يُجۡزَ بِهِۦ وَلَا يَجِدۡ لَهُ ۥ مِن دُونِ ٱللَّهِ وَلِيًّ۬ا وَلَا نَصِيرً۬ا • وَمَن يَعۡمَلۡ مِنَ ٱلصَّـٰلِحَـٰتِ مِن ذَڪَرٍ أَوۡ أُنثَىٰ وَهُوَ مُؤۡمِنٌ۬ فَأُوْلَـٰٓٮِٕكَ يَدۡخُلُونَ ٱلۡجَنَّةَ وَلَا يُظۡلَمُونَ نَقِيرً۬ا ﴾
(It will not be in accordance with your desires (Muslims), nor those of the People of the Scripture (Jews and Christians), whosoever works evil, will have the recompense thereof, and he will not find any protector or helper besides Allah. And whoever does righteous good deeds, male or female, and is a (true) believer ﴿in the Oneness of Allah (Muslim)﴾, such will enter Paradise and not the least injustice, even the size of a Naqira (speck on the back of a date stone), will be done to them) (4: 123-124).
Also, Abu Hurayrah, Abu Wa'il, `Ata', and Al-Hasan said that,
﴿ وَأَحَـٰطَتۡ بِهِۦ خَطِيٓـَٔتُهُ ۥ ﴾
(And his sin has surrounded him) means, "His Shirk (polytheism) has surrounded him.'' Also, Al-A`mash reported from Abu Razin that Ar-Rabi` bin Khuthaym said,
﴿ وَأَحَـٰطَتۡ بِهِۦ خَطِيٓـَٔتُهُ ۥ ﴾
(And his sin has surrounded him), "Whoever dies before repenting from his wrongs.'' As-Suddi and Abu Razin said similarly. Abu Al-`Aliyah, Mujahid, Al-Hasan, Qatadah and Ar-Rabi` bin Anas said that,
﴿ وَأَحَـٰطَتۡ بِهِۦ خَطِيٓـَٔتُهُ ۥ ﴾
(And his sin has surrounded him) refers to major sins. All of these statements carry similar meanings, and Allah knows best.