﴿ يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوا۟ ٱذْكُرُوا۟ نِعْمَةَ ٱللَّهِ عَلَيْكُمْ إِذْ جَآءَتْكُمْ جُنُودٌۭ فَأَرْسَلْنَا عَلَيْهِمْ رِيحًۭا وَجُنُودًۭا لَّمْ تَرَوْهَا ۚ وَكَانَ ٱللَّهُ بِمَا تَعْمَلُونَ بَصِيرًا ﴾

“O YOU who have attained to faith! Call to mind the blessings which God bestowed on you (at the time) when [enemy] hosts came down upon you, where­upon We let loose against them a storm wind and [heavenly] hosts that you could not see: yet God saw all that you did.”

At the battle of Ahzab (in the fifth year of Hijrah) there was a combined attack by Arab tribes and Jews on Madinah. The number of attackers in this battle was about thirteen thousand and the Muslims were not capable of fighting this huge army. But, Almighty God, by His special devices, caused Islam’s enemies to become so terror-stricken that they themselves abandoned the siege of Madinah and retreated. Such difficulties befall the Islamic mission firstly in order to separate the sincere from the insincere and secondly to show to the enemy forces that God Himself is a supporter of His religion. He will not allow it to be vanquished.