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]
The Prophet (Sal-allahu-aleihi-wasallam) said, "If anyone recites surat al-Kahf on Friday, a light will shine brightly for him till the next Friday."