Surah Yunus (Jonah), Verse 19

وَمَا كَانَ النَّاسُ اِلَّاۤ اُمَّةً وَّاحِدَةً فَاخْتَلَفُوْا وَلَوْلَا كَلِمَةٌ سَبَقَتْ مِنْ رَّبِّكَ لَقُضِیَ بَیْنَهُمْ فِیْمَا فِیْهِ یَخْتَلِفُوْنَ ۟

Wa maa kaanan naasu illaaa ummatanw waahidatan fa khtalafoo; wa law laa kalimatun sabaqat mir Rabbika laqudiya bainahum fee maa feehi yakhtalifoon

“Mankind was but one nation, but differed (later). Had it not been for a word that went forth before from thy Lord, their differences would have been settled between them.”

Quran 10:19 (Yusuf Ali Translation)