Surah Yunus, Verse 19
وَمَا كَانَ ٱلنَّاسُ إِلَّآ أُمَّةًۭ وَٰحِدَةًۭ فَٱخْتَلَفُوا۟ ۚ وَلَوْلَا كَلِمَةٌۭ سَبَقَتْ مِن رَّبِّكَ لَقُضِىَ بَيْنَهُمْ فِيمَا فِيهِ يَخْتَلِفُونَ
Translation — Sahih International
And mankind was not but one community [united in religion], but [then] they differed. And if not for a word that preceded from your Lord, it would have been judged between them [immediately] concerning that over which they differ.
Source
Kur'an-ı Kerim, Yûnus Suresi 10:19
https://kuran.diyanet.gov.tr/mushaf/kuran-meal-2/10-suresi-19-ayet