And if We had made it a Quran in a foreign tongue, they surely would have said, Why not its verses have been made clear? What, a book in foreign tongue and the Prophet Arabian. Say you, 'that is a guidance and a cure for the believers.' And those who believe not, in their ears is a plug and to them it is a blindness. They are like those. Who are called from a far off place. [41:44]
It is narrated on the authority of Humran that he heard Uthman saying this: I heard the Messenger of Allah (may peace be upon him) uttering these words (as stated above).