Al Ahzab Ayah 9

يَـٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُواْ ٱذْكُرُواْ نِعْمَةَ ٱللَّهِ عَلَيْكُمْ إِذْ جَآءَتْكُمْ جُنُودٌ فَأَرْسَلْنَا عَلَيْهِمْ رِيحًا وَجُنُودًا لَّمْ تَرَوْهَا‌ۚ وَكَانَ ٱللَّهُ بِمَا تَعْمَلُونَ بَصِيرًا ٩ O believers! Remember Allah’s favour upon you when ?enemy? forces came to ?besiege? you ?in Medina?, so We sent against them a ?bitter? wind and forces you could not see. And Allah is All-Seeing of what you do.