The Quran is a clear Book. It is not subject to errors, confusion or corruption. It is protected by Allah and He has promised to preserve it intact. The Quran was revealed in Arabic. But this does not mean that the Quran specifically addressed to the Arabs only.
Some people are inclined to deny the universal character of the Quranic message.
In order to prove their point they like to pick upon statements such as this verse one. They contend on that basis that the Quran is exclusively addressed to Arabs and is meant for none other. This is a very superficial statement, which shows very little understanding. For any universal message will have to be expressed in some language of the world. This is the only natural way for any message, or movement to spread and be universalized.