Narrated Ibn `Abbas:

(regarding) the explanation of"... It throws sparks as Al-Qasr..." (V. 77:32):

We used to collect logs of wood, three cubits long or longer, to store for heating purposes in winter, and we used to call it Al-Qasr, it also means a castle or a fort.

As if they were Jimalatun Sufr (yellow camels or bundles of ropes)" (V.77:33): means the ropes of a ship which are made in bundles till it become as wide as men's waists