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.
Explanation & Benefits
Shaykh Abdul Sattar al-Hammad
Hadith Commentary:
The purpose here is to interpret the noble verse, that on the Day of Resurrection, the sparks of Hell will be so enormous as to resemble great beams of wood.
Imam Bukhari rahimahullah has given preference to this meaning, but the general interpretation is that on the Day of Resurrection, Hell will throw out sparks as large as great palaces.
This meaning applies when "qasr" is read with a sukun (jazm) on the letter "ṣād", whereas if it is read with a fatḥah on the "ṣād", then the meaning is as Imam Bukhari rahimahullah has chosen.
And Allah knows best.
Source: Hidayat al-Qari: Commentary on Sahih Bukhari, Urdu, Page: 4932