وَيَوْمَ حُنَيْنٍ ۙ إِذْ أَعْجَبَتْكُمْ كَثْرَتُكُمْ فَلَمْ تُغْنِ عَنكُمْ شَيْئًا وَضَاقَتْ عَلَيْكُمُ الْأَرْضُ بِمَا رَحُبَتْ ثُمَّ وَلَّيْتُم مُّدْبِرِينَ
“On the Day of Hunayn, when your quantity deceived you (i.e., you felt arrogant), all of your quantity was not able to help you. And the earth, despite the fact that it is so vast, felt very narrow and constrained for you, and all of you turned and fled.”
One of only two battles named explicitly in the Qur'an (with Badr); describes the Muslims' overconfidence in their numbers availing them nothing when the ambush struck.