Narrated Ibn 'Abbas:
(regarding) the explanation of "... It throwssparks as Al-Qasr ..." (V. 77:32):We used to collect logs of wood, threecubits long or longer, to store for heatingpurposes in winter, and we used to call it Al-Qasr, it also means a castle or a fort."As if they were Jimalatun Sufr (yellowcamels or bundles of ropes)" (V.77:33):means the ropes of a ship which are made inbundles till it become as wide as men's waists.
USC-MSA web (English) reference: Vol. 1, Book 60, Hadith 455
Arabic reference: Book 65, Hadith 4933