Verse 42

إِذْ أَنتُم بِٱلْعُدْوَةِ ٱلدُّنْيَا وَهُم بِٱلْعُدْوَةِ ٱلْقُصْوَىٰ وَٱلرَّكْبُ أَسْفَلَ مِنكُمْ وَلَوْ تَوَاعَدتُّمْ لَٱخْتَلَفْتُمْ فِى ٱلْمِيعَـٰدِ وَلَـٰكِن لِّيَقْضِىَ ٱللَّهُ أَمْرًا كَانَ مَفْعُولًا لِّيَهْلِكَ مَنْ هَلَكَ عَنۢ بَيِّنَةٍ وَيَحْيَىٰ مَنْ حَىَّ عَنۢ بَيِّنَةٍ وَإِنَّ ٱللَّهَ لَسَمِيعٌ عَلِيمٌ

When you occupied the high ground, they occupied the low ground and their cavalry was even lower. Had you arranged this you would have botched it, however, God preordains every task according to how it is to be done in order to annihilate those who are to be annihilated for a specific reason and keep alive those who are to stay alive for a specific reason. And indeed God is All Hearer, All Knowing.