Surah Al-Baqarah, verse 251

فَهَزَمُوهُم بِإِذْنِ ٱللَّهِ وَقَتَلَ دَاوُۥدُ جَالُوتَ وَءَاتَىٰهُ ٱللَّهُ ٱلْمُلْكَ وَٱلْحِكْمَةَ وَعَلَّمَهُۥ مِمَّا يَشَآءُ ۗ وَلَوْلَا دَفْعُ ٱللَّهِ ٱلنَّاسَ بَعْضَهُم بِبَعْضٍ لَّفَسَدَتِ ٱلْأَرْضُ وَلَـٰكِنَّ ٱللَّهَ ذُو فَضْلٍ عَلَى ٱلْعَـٰلَمِينَ ﴿٢٥١﴾

2:251 Thus they defeated them by Allah’s grace, and David killed Goliath, and Allah gave him the kingdom and wisdom and taught him whatever He willed. Were it not for Allah to repel some people by others, the earth would be filled with corruption, but Allah is All-Gracious to the worlds