The Reason and Wisdom Behind the Defeat at Uhud

Allah said,

أَوَ لَمَّا أَصَـبَتْكُمْ مُّصِيبَةٌ

Immediately later, in verse 166, the words fa bi idhnillahi: فَبِإِذْنِ اللَّـه indicate that whatever happened there was with the leave and will of Allah Almighty operating behind which are many wise divine arrangements, some of them having been explained earlier. One such wise arrangement is that Allah will 'see' His true believers, and the hypocrites too, that is, the sincerity of Muslims and the hypocrisy of the hypocrites will become so clear that everybody could see it for himself. Here, the reference to Allah's knowing or seeing means seeing in the perspective of our own sense-experience in the mortal world. Otherwise, as far as Allah is concerned, He knows and sees everything, all the time. So, the wise arrangement became all the more clear when, at the time of the trial, the hypocrites bowed out of the harm's way while true Muslims stood undaunted' in the middle of the battle front.