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 Aswad b. Hilal that he heard Mu'adh say this: The Messenger of Allah (may peace be upon him) called, me and I replied to him. He (the Holy Prophet) said: Do you know the right of Allah upon the people? and then followed the hadith (mentioned above).