Musnad Ahmad 30:3800

Hassan narrated to us, Abd al-Rahman ibn Abd Allah ibn Dinar narrated to us, from Zayd ibn Aslam, from Ata ibn Yasar, from Abu Hurayrah, from the Prophet (peace and blessings of Allah be upon him), who said: "The molar of the disbeliever is like Uhud, and his thigh is like al-Bayda', and his seat in the Fire is as the distance between Qudayd and Makkah. And the thickness of his skin is forty-two cubits by the cubit of the Compeller (al-Jabbar)."