Ibrahim - 14:4

وَمَا أَرْسَلْنَا مِن رَّسُولٍ إِلاَّ بِلِسَانِ قَوْمِهِ لِيُبَيِّنَ لَهُمْ فَيُضِلُّ اللّهُ مَن يَشَاء وَيَهْدِي مَن يَشَاء وَهُوَ الْعَزِيزُ الْحَكِيمُ
[14:4]
And We did not send any messenger but with the language of his people, so that he might explain to them clearly; then Allah makes whom He pleases err and He guides whom He pleases and He is the Mighty, the Wise.
We sent not a messenger except (to teach) in the language of his (own) people, in order to make (things) clear to them. Now Allah leaves straying those whom He pleases and guides whom He pleases: and He is Exalted in power, full of Wisdom.
And We never sent a messenger save with the language of his folk, that he might make (the message) clear for them. Then Allah sendeth whom He will astray, and guideth whom He will. He is the Mighty, the Wise.