A Quranic Journal: Surah al-Fil ayah 3

The birds were flying in groups... The significance of this event is far reaching and the lessons deduced from mentioning it in the Qur'an are numerous. It first suggests that Allah did not want the polytheists to take the responsibility of protecting His House, in spite of the fact that they held it in deep respect and sought security in being its neighbours. When He willed to preserve the House and made it clear that He Himself was its protector who looked after it, He left the polytheists to be defeated by the Abyssinians. The Divine Will then directly intervened to repel the aggression and preserve the sacred House of Allah. Thus the polytheists did not have the chance to hold the protection of the House as a 'favour they did to Allah' or as "an act of honour". If they did, they would have been prompted by the fanatic impulses of Ignorance. This point gives considerable weight to the argument that the Divine Will of destroying the aggressors was accomplished through preternatural rules.