Surah Al-Anfal · 8:63

وَأَلَّفَ بَيْنَ قُلُوبِهِمْ ۚ لَوْ أَنفَقْتَ مَا فِى ٱلْأَرْضِ جَمِيعًۭا مَّآ أَلَّفْتَ بَيْنَ قُلُوبِهِمْ وَلَـٰكِنَّ ٱللَّهَ أَلَّفَ بَيْنَهُمْ ۚ إِنَّهُۥ عَزِيزٌ حَكِيمٌۭ

“He brought their hearts (hearts of the believers) together. Had you spent all the riches in the earth, you could not have united their hearts. But Allah has united them. Indeed, He is Almighty, All-Wise.”