Surah Muhammad (Muhammad), Verse 30

وَلَوْ نَشَآءُ لَاَرَیْنٰكَهُمْ فَلَعَرَفْتَهُمْ بِسِیْمٰهُمْ وَلَتَعْرِفَنَّهُمْ فِیْ لَحْنِ الْقَوْلِ وَاللّٰهُ یَعْلَمُ اَعْمَالَكُمْ ۟

Wa law nashaaa'u la-arainaakahum fala 'araftahum bi seemaahum; wa lata'rifan nahum fee lahnil qawl; wallaahu ya'lamu a'maalakum

“Had We so willed, We could have shown them up to thee, and thou shouldst have known them by their marks: but surely thou wilt know them by the tone of their speech! And Allah knows all that ye do.”

Quran 47:30 (Yusuf Ali Translation)