Chapter: Yusuf; Verse 2
We have sent it down as an Arabic Qur’an, in order that ye may learn wisdom. (Translation A.Yusuf Ali)
Chapter: Ibrahim; Verse: 4
We sent not a messenger except (to teach) in the language of his (own) people, in order to make (things) clear to them. Now Allah leaves straying those whom He pleases and guides whom He pleases: and He is Exalted in power, full of Wisdom. (Translation A.Yusuf Ali)
Chapter: Fussilat (Hamem Al-Sajida) Verse: 44
Had We sent this as a Qur’an (in the language) other than Arabic, they would have said: “Why are not its verses explained in detail? What! (a Book) not in Arabic?” Say: “It is a Guide and a Healing to those who believe; and for those who believe not, there is a deafness in their ears, and it is blindness in their (eyes): They are (as it were) being called from a distant!” (Translation A.Yusuf Ali)
Chapter: Al-Shura; Verse: 7
Thus have We sent by inspiration to thee Arabic Qur’an: that thou mayest warn the Mother of Cities and all around her,-and warn (them) of the Day of Assembly, of which there is no doubt: (when) some will be in the Garden, and some in the Blazing Fire. (Translation A.Yusuf Ali)
Qur’an, the book of Islam, is in Arabic but non-Arabic Muslims of the world in particular and the Arabic speaking Muslims in general take this language for granted and is assumed as the language of Heaven الجنۃ. Is this a case and does such a notion preposterous or has a leg to stand on? There is no other avenue to gauge this belief except Qur’an itself.
Verse 2, chapter Yusuf, guides Muhammad, prophet of Islam, that message of this book is in Arabic so that you can learn wisdom.
Verse 4, chapter Ibrahim, provides the raison d’etre and importance of the message to be given in the language of the people to which it is to be addressed so that ordain should be clear to be followed upon.
Verse 44, chapter Fussilat, is imbued with verbose and emphatically elucidatory by debating that if the book of Islam by Muhammad, prophet of Islam, is another language then the subjects i.e. Arabs of Mecca, would have amazed.
Verse 7, chapter Al-Shura, also makes the point that this book is in Arabic and the duty of the promulgator is to warn the inhabitants and all around it to be righteous.
So to emphasize that Arabic is the language of heavens and to be a pivotal for every Muslim to learn for salvage in hereafter is contrary to the teachings of Qur’an and Islam.