Translation of the verse 4 from Surah Al-Fil : Number of verses 5 - - page 601 - Part 30.
Striking them with stones of Sijjil.
Striking them with stones of hard clay,
(105:4) which smote them with stones of baked clay, *6
*6) Litrerally, bi hijarat-im-min sijjil means "stones of sijjil type." Ibn `Abbas says that sijjil is the Arabic version of the Persian sang and gil, and it implies the stones made from clay and become hard when baked. The Qur'an also confirms the same. In Surah Hud :82 and Al-Hijr: 74, it has been said that stones of baked clay (sijjin were rained on the people of Lot, and about the same stones in Adh-Dhariyat: 33, it has been said that they were the stones made from clay (hijarat-im min tin).
Maulana Hamid-ad-Din Farahi, who in the present age has done valuable work on the research and determination of the meaning and content of the Qur'an regards the people of Makkah and other Arabians as the subject of tarmihim in this .verse, who are the addressees of alam tara. About the birds he says that they were not casting stones but had come to eat the dead bodies of the people of theelephant. A resume of the arguments he has given for this interpretation is that it is not credible that `Abdul Muttalib should have gone before ,Abrahah and demanded his camels instead of pleading for the Ka`bah, and this also is not credible that the people of Quraish and the other Arabs who had come for Hajj, did not resist the invaders and leaving the Ka`bah at their mercy had gone off to the mountains. Therefore, what actually happened was that the Arabs pelted the army of Abrahah with stones, and Allah by sending a stormy wind charged with stones, destroyed it completely; thee the birds were sent to eat the dead bodies of the soldiers. But, as we have already explained in the Introduction, the tradition does not only say that `Abdul Muttalib had gone to demand his camels but it says that he did not demand the camels at all but tried to dissuade Abrahah from attacking the Ka`bah. We have already explained that according to all reliable traditions, Abrahah's army had come in Muharram when the pilgrims had gone back and also it was beyond the power of Quraish and other Arab tribes living in the surrounding areas to resist and fight an army 60,000 strong. They had hardly been able to muster a force ten to twelve thousand strong on the occasion of the Battle of the Trench (Ahzab) with t he help of the Arab pagans and Jewish tribes then how could they have mustered courage to encounter an army, 60,000 strong? However. even if all these arguments are rejected and the sequence of the verses of Surah Al-Fil only is kept in view, this interpretation is seen to go against it. If it were so that the stones were cast by the Arabs and the people of the elephant were rendered as chaff, and then the birds came to eat their dead bodies, the order would be this: "You were pelting them with stones of baked clay, then Allah rendered them as chaff eaten up, and then Allah sent upon them swarms of birds. " but here we see that first Allah has made mention of sending swarms of birds; this is immediately followed by tarmihim bi-hijarat-im min-sijjil (which were pelting them with stones of baked clay); and then at the end it is said that Allah made them as straw eaten up.
Source : Al-Fil Verse 4: Striking them with stones of hard clay,