Sahih Bukhari
Prophetic Commentary on the Quran (Tafseer of the Prophet (PBUH))
Volume: 006 / Book Number: 060 / Hadith Number: 455
Narrated Ibn Abbas:
(as regards the explanation of Hadith 454). 'Indeed, it (Hell) throws about sparks (huge) as Forts.' We used to collect wood in the form of logs, three cubits long or shorter. for heating purposes in winter., and we used to call such wood, the Qasr.