Abū Hurayrah—attributing it to the Prophet—said:

“The span between the shoulders of the disbeliever in Hell is the distance of a three-day journey for a swift rider.”

Al-Bayhaqī remarked: Al-Bukhārī narrated it through Muʿādh ibn Asad from al-Faḍl ibn Mūsā, and Muslim narrated it through Abū Kurayb and others from Ibn Fuḍayl, but neither of them used the phrase “attributing it.” (1)

[Another route from him]
Al-Bazzār said: Al-Ḥusayn (2) ibn al-Aswad narrated to us; Muḥammad ibn Fuḍayl narrated to us; ʿĀṣim ibn Kulayb narrated to us; from his father; from Abū Hurayrah, who said that the Messenger of Allah ﷺ stated:

“The molar tooth of the disbeliever is like [Mount] Uḥud, his thigh is like al-Wariqān, and the thickness of his skin is forty cubits.”

Al-Bazzār then commented: “A better chain from Abū Hurayrah is not known to us, and we have heard it only from al-Ḥusayn ibn al-Aswad.” (3)

Imām Aḥmad said: Ḥasan ibn Mūsā narrated to us; Ḥammād ibn Salamah narrated to us; from Dāwūd ibn Abī Hind; from ʿAbd Allāh ibn Qays, who said: I heard al-Ḥārith ibn Uqays relate that Abū Bazza said: I heard the Messenger of Allah ﷺ say:

“Among my community are those who will intercede for more people than [the tribes of] Rabīʿah and Muḍar combined, and among my community are those who will be made so enormous for the Fire that he will become one of its corners.”

Aḥmad also narrated it through Muḥammad ibn Abī ʿAdī, from Dāwūd ibn Abī Hind, with the same chain. (4)

He (Aḥmad) further said: Ismāʿīl ibn Ibrāhīm narrated to us; Abū Ḥayyān narrated to us [Yazīd ibn Ḥayyān al-Taymī related it to me]; and Zayd ibn Arqam narrated to us, saying: “A man from the people of Hell will be enlarged for the Fire until a single molar tooth of his becomes like [Mount] Uḥud.” (5)

As for the ḥadīth transmitted by Imām Aḥmad: ‘Yahyā narrated to us; from Ibn ʿAjlān; from ʿAmr ibn Shuʿayb; from his father; from his grandfather; from the Prophet ﷺ, who said:

“The arrogant will be gathered on the Day of Resurrection like tiny ants in human form; humiliation will engulf them from every side. They will then be herded into a prison in Hell called Būlas. The fiercest of Fires will cover them, and they will be given to drink from ṭīnatu l-khabāl—the filth that oozes from the inhabitants of the Fire.”’

Al-Tirmidhī and al-Nasāʾī likewise narrated it from Suwayd ibn Naṣr, from Ibn al-Mubārak, from Ibn ʿAjlān with this chain, and al-Tirmidhī graded it ḥasan. (6)

What is meant is that the arrogant will be brought to the place of standing in that diminutive state and will remain among the rest of creation in that form. Then, once they are driven to Hell and enter it, their bodies will be magnified there—as the aforementioned ḥadīths indicate—so that the punishment will be even harsher and more intense.