Battle of Ḥunain

لَقَدْ نَصَرَكُمُ ٱللَّهُ فِى مَوَاطِنَ كَثِيرَةٍ ۙ وَيَوْمَ حُنَيْنٍ ۙ إِذْ أَعْجَبَتْكُمْ كَثْرَتُكُمْ فَلَمْ تُغْنِ عَنكُمْ شَيْـًٔا وَضَاقَتْ عَلَيْكُمُ ٱلْأَرْضُ بِمَا رَحُبَتْ ثُمَّ وَلَّيْتُم مُّدْبِرِينَ

God has helped you [believers] on many battlefields, even on the day of the Battle of Hunayn. You were well pleased with your large numbers, but they were of no use to you: the earth seemed to close in on you despite its spaciousness, and you turned tail and fled.

ثُمَّ أَنزَلَ ٱللَّهُ سَكِينَتَهُۥ عَلَىٰ رَسُولِهِۦ وَعَلَى ٱلْمُؤْمِنِينَ وَأَنزَلَ جُنُودًا لَّمْ تَرَوْهَا وَعَذَّبَ ٱلَّذِينَ كَفَرُوا۟ ۚ وَذَٰلِكَ جَزَآءُ ٱلْكَـٰفِرِينَ

Then God sent His calm down to His Messenger and the believers, and He sent down invisible forces. He punished the disbelievers- this is what the disbelievers deserve-

ثُمَّ يَتُوبُ ٱللَّهُ مِنۢ بَعْدِ ذَٰلِكَ عَلَىٰ مَن يَشَآءُ ۗ وَٱللَّهُ غَفُورٌ رَّحِيمٌ

but God turns in His mercy to whoever He will. God is most forgiving and merciful.