Why is the Quran in Arabic?

Why is the Quran in Arabic?

Is the Arabic Alphabet or Arabic a Sacred Language?
The Quran does not mention that any language is sacred. On the contrary, the difference of languages is one of the proofs of Allah:
“And of His signs is the creation of the heavens and the earth, and the difference of your languages and colour’s…” (The Quran, al-Rum [30] 22).

Why is the Quran in Arabic?
The reason why the Quran is in Arabic is because the Messenger of Allah and the first muslims were Arabs (The Quran, Fussilat [41] 44; al-Nahl [16] 103; Yusuf [12] 2). Every messenger was sent in the language of his people: “And We sent them every messenger only with the language of his people so he might make clear…” (Quran, Ibrahim [14] 4). That is why the Torah was sent in Hebrew and the Bibel in Aramaic. Otherwise they would all have been in Arabic.

Will Arabic be spoken in the grave interrogation and in Paradise?
The Quran does not give any information about the grave interrogation and the language that will be spoken in Paradise.

In conclusion, there is no ethnic distinction, superiority or inferiority in the sight of Allah.