Sura Āl-ʿImrān 3:56

فَأَمَّا ٱلَّذِينَ كَفَرُوا۟ فَأُعَذِّبُهُمْ عَذَابًا شَدِيدًا فِى ٱلدُّنْيَا وَٱلْأَخِرَةِ وَمَا لَهُم مِّن نَّٰصِرِينَ

fa-ammā lladhīna kafarū fa-uʿadhdhibuhum ʿadhāban shadīdan fī l-dunyā wa-l-akhirati wa-mā lahum min nāṣirīna

"As to those who reject faith, I will punish them with terrible agony in this world and in the Hereafter, nor will they have anyone to help."

Sura al-Māʾidah 5:115

قَالَ ٱللَّـهُ إِنِّى مُنَزِّلُهَا عَلَيْكُمْ فَمَن يَكْفُرْ بَعْدُ مِنكُمْ فَإِنِّىٓ أُعَذِّبُهُۥ عَذَابًا لَّآ أُعَذِّبُهُۥٓ أَحَدًا مِّنَ ٱلْعَٰلَمِينَ

qalā allāhu innī munazziluhā ʿalaykum fa-man yakfur baʿdu minkum fa-innī uʿadhdhibuhu ʿadhāban lā uʿadhdhibuhu aḥadan mina l-ʿālamīna

Allah said: "I will send it down unto you: But if any of you after that resisteth faith, I will punish him with a penalty such as I have not inflicted on any one among all the peoples."

Sura al-Tawbah 9:66

لَا تَعْتَذِرُوا۟ قَدْ كَفَرْتُم بَعْدَ إِيمَٰنِكُمْ إِن نَّعْفُ عَن طَآئِفَةٍ مِّنكُمْ نُعَذِّبْ طَآئِفَةًۢ بِأَنَّهُمْ كَانُوا۟ مُجْرِمِينَ

lā taʿtadhirū qad kafartum baʿda īmānikum in nnaʿfu ʿan ṭāʾifatin minkum nuʿadhdhib ṭāʾifatan bi-annahum kānū mujrimīna

Make ye no excuses: ye have rejected Faith after ye had accepted it. If We pardon some of you, We will punish others amongst you, for that they are in sin.

Sura al-Tawbah 9:101

وَمِمَّنْ حَوْلَكُم مِّنَ ٱلْأَعْرَابِ مُنَٰفِقُونَ وَمِنْ أَهْلِ ٱلْمَدِينَةِ مَرَدُوا۟ عَلَى ٱلنِّفَاقِ لَا تَعْلَمُهُمْ نَحْنُ نَعْلَمُهُمْ سَنُعَذِّبُهُم مَّرَّتَيْنِ ثُمَّ يُرَدُّونَ إِلَىٰ عَذَابٍ عَظِيمٍ

wa-mimman ḥawlakum mina l-aʿrābi munāfiqūna wa-min ahli l-madīnati maradū ʿalā l-nifāqi lā taʿlamuhum naḥnu naʿlamuhum sa-nuʿadhdhibuhum marratayni thumma yuraddūna ilā ʿadhābin ʿaẓīmin

Certain of the desert Arabs round about you are hypocrites, as well as (desert Arabs) among the Medina folk: they are obstinate in hypocrisy: thou knowest them not: We know them: twice shall We punish them: and in addition shall they be sent to a grievous penalty.

Sura al-Kahf 18:87

قَالَ أَمَّا مَن ظَلَمَ فَسَوْفَ نُعَذِّبُهُۥ ثُمَّ يُرَدُّ إِلَىٰ رَبِّهِۦ فَيُعَذِّبُهُۥ عَذَابًا نُّكْرًا

qalā ammā man ẓalama fa-sawfa nuʿadhdhibuhu thumma yuraddu ilā rabbihi fa-yuʿadhdhibuhu ʿadhāban nnukran

He said: "Whoever doth wrong, him shall we punish; then shall he be sent back to his Lord; and He will punish him with a punishment unheard-of (before).

Sura al-Naml 27:21

لَأُعَذِّبَنَّهُۥ عَذَابًا شَدِيدًا أَوْ لَأَا۟ذْبَحَنَّهُۥٓ أَوْ لَيَأْتِيَنِّى بِسُلْطَٰنٍ مُّبِينٍ

la-uʿadhdhibannahu ʿadhāban shadīdan aw la-ādhbaḥannahu aw la-yaʾtiyannī bi-sulṭānin mubīnin

"I will certainly punish him with a severe penalty, or execute him, unless he bring me a clear reason (for absence)."

Sura al-Fatḥ 48:25

هُمُ ٱلَّذِينَ كَفَرُوا۟ وَصَدُّوكُمْ عَنِ ٱلْمَسْجِدِ ٱلْحَرَامِ وَٱلْهَدْىَ مَعْكُوفًا أَن يَبْلُغَ مَحِلَّهُۥ وَلَوْلَا رِجَالٌ مُّؤْمِنُونَ وَنِسَآءٌ مُّؤْمِنَٰتٌ لَّمْ تَعْلَمُوهُمْ أَن تَطَـُٔوهُمْ فَتُصِيبَكُم مِّنْهُم مَّعَرَّةٌۢ بِغَيْرِ عِلْمٍ لِّيُدْخِلَ ٱللَّـهُ فِى رَحْمَتِهِۦ مَن يَشَآءُ لَوْ تَزَيَّلُوا۟ لَعَذَّبْنَا ٱلَّذِينَ كَفَرُوا۟ مِنْهُمْ عَذَابًا أَلِيمًا

humu lladhīna kafarū wa-ṣaddūkum ʿani l-masjidi l-ḥarāmi wa-l-hadya maʿkūfan an yablugha maḥillahu wa-lawlā rijālun muʾminūna wa-nisāʾun muʾminātun lam taʿlamūhum an taṭaʾūhum fa-tuṣībakum minhum maʿarratun bi-ghayri ʿilmin li-yudkhila allāhu fī raḥmatihi man yashāʾu law tazayyalū la-ʿadhdhabnā lladhīna kafarū minhum ʿadhāban alīman

They are the ones who denied Revelation and hindered you from the Sacred Mosque and the sacrificial animals, detained from reaching their place of sacrifice. Had there not been believing men and believing women whom ye did not know that ye were trampling down and on whose account a crime would have accrued to you without (your) knowledge, (Allah would have allowed you to force your way, but He held back your hands) that He may admit to His Mercy whom He will. If they had been apart, We should certainly have punished the Unbelievers among them with a grievous Punishment.

Sura al-Ṭalāq 65:8

وَكَأَيِّن مِّن قَرْيَةٍ عَتَتْ عَنْ أَمْرِ رَبِّهَا وَرُسُلِهِۦ فَحَاسَبْنَٰهَا حِسَابًا شَدِيدًا وَعَذَّبْنَٰهَا عَذَابًا نُّكْرًا

wakaayyin min qaryatin ʿatat ʿan amri rabbihā wa-rusulihi fa-ḥāsabnāhā ḥisāban shadīdan wa-ʿadhdhabnāhā ʿadhāban nnukran

How many populations that insolently opposed the Command of their Lord and of His messengers, did We not then call to account,- to severe account?- and We imposed on them an exemplary Punishment.