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 Thabit that Anas said: We were forbidden in the Holy Qur'an that we should ask about anything from the Messenger of Allah (may peace be upon him) and then Anas reported the hadith in similar words.