I heard the Prophet (ﷺ) saying, "The person who will have the least punishment from amongst the Hell Fire people on the Day of Resurrection, will be a man under whose arch of the feet a smoldering ember will be placed so that his brain will boil because of it."
Sahih al-Bukhari Book 81, Hadith 150
← Previous Hadith Allah's Messenger (ﷺ) said, "When the people of Paradise have entered Paradise, and the people of the Fire have entered the Fire, Allah will say. 'Take out (of the Fire) whoever has got faith equal to a mustard seed in his heart.' They will come out, and by that time they would have burnt and became like coal, and then they will be thrown into the river of Al-Hayyat (life) and they will spring up just as a seed grows on the bank of a rainwater stream." The Prophet (ﷺ) said, "Don't you see that the germinating seed comes out yellow and twisted?"

Sahih al-Bukhari Book 81, Hadith 149 Next Hadith → I heard the Prophet (ﷺ) saying, "The least punished person of the (Hell) Fire people on the Day of Resurrection will be a man under whose arch of the feet two smoldering embers will be placed, because of which his brain will boil just like Al-Mirjal (copper vessel) or a Qum-qum (narrow-necked vessel) is boiling with water."

Sahih al-Bukhari Book 81, Hadith 151