Ali ‘Imran Ayah 166

وَمَآ أَصَـٰبَكُمْ يَوْمَ ٱلْتَقَى ٱلْجَمْعَانِ فَبِإِذْنِ ٱللَّهِ وَلِيَعْلَمَ ٱلْمُؤْمِنِينَ ١٦٦ So what you suffered on the day the two armies met was by Allah’s Will, so that He might distinguish the ?true? believers