Indeed, We have sent it down as an Arabic Qur'an that you (12:2)

Almuntakhab Fi Tafsir Alquran Alkarim

it is a Book We have revealed in Arabic literary form, that you people may hopefully comprehend its inimitability and employ the faculty of reason in forming conclusions

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(12:2) We have sent it down as Qur'an *1 in Arabic so that you (Arabs) may understand it well. *2

Indeed, We have sent it down as an Arabic Qur'an that you meaning

*1) The Arabic word (Qur`an: "to read") is originally the infinitive form of the verb When the infinitive form of a verb in Arabic is used as a name, it implies that that thing (or person) possesses the characteristics in their perfection. This Book has been named "Qur'an" to indicate that it is meant to be read by all and sundry and is to be read often and over and over again.
*2) This does not mean that this Book has been sent down exclusively for the Arabs. What it means is only this: "Of all the people, O Arabs, you should understand the excellences of the Qur'an, which are a sure proof of its being Divine Revelation, for it is in your own language and you have no excuse to put forward that it is in a foreign language which you do not understand. "
Some people wrongly infer from this verse that this Book had been sent down for the Arabs and not for the non-Arabs; therefore, they assert, it cannot be claimed that it is the Guidance for the whole mankind. But obviously this is a frivolous objection raised by hose who do not understand its real significance. It is obvious that a book, though meant for universal guidance, will necessarily have to be put in words in some language so that the people speaking that language should understand its teachings and then become the means of conveying its guidance to other peoples. This is the only natural way of spreading the message of a movement on a universal scale.
 

Indeed, We have sent it down as an Arabic Qur'an that you meaning in Urdu

ہم نے اسے نازل کیا ہے قرآن بنا کر عربی زبان میں تاکہ تم (اہل عرب) اس کو اچھی طرح سمجھ سکو