When the People of Hell enter the Fire they will be huge in size, in a form that none can comprehend, except the One Who Created them.

According to a hadith narrated by Abu Hurayrah, the Messenger of Allah (saw) said: “The distance between the shoulders of the Kaafir in Hell will be like three day’s traveling for a fast rider(Muslim, 4/290)

Abu Hurayrah reported that the Messenger of Allah (saw) said: “The molar of the kaafir or the eye-tooth of the kaafir, will be like Uhud, and the thickness of his skin will be like a journey of three (days)“. (Muslim, 4/2189, at-Tirmidhi, al-Haakim, Ibn Maajah and Ahmad)

Zayd ibn Arqam said, “The man who is destined for Hell will become huge in preparation for it, so that one of his molars will be as big as Mount Uhud“.

This is narrated by Ahmad, who attributes it to the Prophet (saw) but Zayd did not state that he heard it from the Prophet (saw). (Silsilat al-Ahadith as-Sahihah, 4/131, al-Albaani said its isnaad is saheeh according to Ibn Maajah and Ahmad)

Abu Hurayrah reported that the Prophet (saw) said: “The kaafir’s skin will be forty-two cubits thick and his molar will be like Uhud and the space he occupies will be as wide as the distance between Makkah and Madinah.” (at-Tirmidhi) (Mishkaat al-Masaabeeh 3/103, sahih hasan)

Abu Hurayrah (ra) reported that the Prophet (saw) said: “The molar of the kaafir on the Day of Resurrection will be like Uhud, and the thickness of his skin will be seventy cubits. His upper arm will be like al-Bayda’, his thigh will be like Warqaan and the space he occupies will be like the distance between me and ar-Rabdhah” (al-Haakim and Ahmad – Silsilah al-Ahadith as-Sahihah, 4/94. al-Baydaa` could be the name of a mountain or it may refer to the well-known city in Morocco)

This increasing of the kaafir’s body size will increase his suffering and torment. Commenting on the hadith narrated by Muslim on this subject, an-Nawawi said, “All of this is in order to intensify the suffering, and all of this is possible for Allah (swt). We must believe in it, because the truthful (Prophet) has told us about it” [Sharh an-Nawawi ‘alaa Muslim, 17/186]. Ibn Katheer in a comment on these hadith said, “So that their punishment and suffering may be more severe, as Allah (swt) the Severe in punishment says:
…that they may taste the Penalty“. (4:46)
[Ibn Katheer, an-Nihayah, 2/139]