Therefore I have warned you of a Fire Talazza.
Mujahid said, "Blazing."
Imam Ahmad recorded from Simak bin Harb that he heard An-Nu`man bin Bashir giving a sermon, in which he said,
"I heard the Messenger of Allah giving a sermon, in which he said;
أَنْذَرْتُكُمُ النَّار
I have warned you of the Fire.
And he said it in such a voice that if a man was in the marketplace he could hear it from where I am standing now.
And he said it (with such force) that the garment that was on his shoulder fell down to his feet."
Imam Ahmad recorded from Abu Ishaq that he heard An-Nu`man bin Bashir giving a sermon, in which he said, "I heard the Messenger of Allah saying,
إِنَّ أَهْوَنَ أَهْلِ النَّارِ عَذَابًا يَوْمَ الْقِيَامَةِ رَجُلٌ تُوضَعُ فِي أَخْمَصِ قَدَمَيْهِ جَمْرَتَانِ يَغْلِي مِنْهُمَا دِمَاغُه
Verily, the person to be punished lightest of the people of the Fire on the Day of Judgement will be a man who will have placed on the soles of his feet two coals that will cause his brain to boil."
Imam Al-Bukhari also recorded this narration.
Muslim recorded that Abu Ishaq narrated from An-Nu`man bin Bashir that the Messenger of Allah said,
إِنَّ أَهْوَنَ أَهْلِ النَّارِ عَذَابًا مَنْ لَهُ نَعْلَنِ وَشِرَاكَانِ مِنْ نَارٍ يَغْلِي مِنْهُمَا دِمَاغُهُ كَمَا يَغْلِي الْمِرْجَلُ مَا يَرَى أَنَّ أَحَدًا أَشَدُّ مِنْهُ عَذَابًا وَإِنَّهُ لَاَهْوَنُهُمْ عَذَابًا
Verily, the lightest punishment received by the people of the Hellfire will be a man who will have two sandals whose straps will be made of fire that will cause his brain to boil just as a cauldron boils. Yet he will not think that anyone is receiving a torment more severe than him, even though he will be receiving the lightest punishment of them.
Allah says,
لَاا يَصْلَاهَا إِلاَّ الاْاَشْقَى