Surah Al-Qasas (28) — Ayah 85

(Ayah 85) ➊ In { اِنَّ الَّذِيْ فَرَضَ عَلَيْكَ الْقُرْاٰنَ …: ’’ مَعَادٍ ‘‘}, the tanween is for magnification, therefore the translation is made as "the place of return of great glory." By making the Qur’an obligatory is meant the obligation to act upon it, to convey it to all the people of the world, and to strive (jihad) for it.
➋ {لَرَآدُّكَ اِلٰى مَعَادٍ :} Previously it was said: {’’ وَ الْعَاقِبَةُ لِلْمُتَّقِيْنَ ‘‘} Now, for the Messenger of Allah (peace be upon him), the mention of this good outcome is made, and the surah ends with magnificent glad tidings, that is, the Allah who has imposed upon you the obligation of acting upon the Qur’an and inviting towards it, He is the One who will bring you to a magnificent end as a result of your effort, toil, and fulfillment of duty, both in this world and in the Hereafter. In this world, in such a way that you will migrate from this city of Makkah and then return to it again, and you will return in such a splendid manner that the entire Arabian Peninsula will be under your control. As narrated in Sahih Bukhari (4773) from Ibn Abbas (may Allah be pleased with them both), that by {’’ مَعَادٍ ‘‘} is meant Makkah Mukarramah. Thus, in the eighth year after Hijrah, this promise of Allah was fulfilled and you entered Makkah Mukarramah in a victorious manner, and in the Hereafter, He will bring you to the magnificent station of praise (maqam mahmud), due to which all the former and latter people will admire you. It is called {’’ مَعَادٍ ‘‘} because in the Noble Qur’an, the Hereafter is declared as the place of return for everyone, as He said: «{ وَ اتَّقُوْا يَوْمًا تُرْجَعُوْنَ فِيْهِ اِلَى اللّٰهِ }» [ البقرۃ : ۲۸۱ ] “And fear the Day when you will be returned to Allah.” And He said: «{ ثُمَّ اِلَيْهِ تُرْجَعُوْنَ }» [ البقرۃ : ۲۸ ] “Then you will be returned to Him.” And He said: «{ اِلَى اللّٰهِ مَرْجِعُكُمْ }» [ المائدۃ : ۴۸ ] “To Allah is the return of all of you.” Some of the commentators have taken {’’ مَعَادٍ ‘‘} to mean Makkah and some have taken it to mean Paradise; both views are correct in their own place.
➌ { قُلْ رَّبِّيْۤ اَعْلَمُ مَنْ جَآءَ بِالْهُدٰى … :} This prophecy, that your Lord will return you to this very Makkah in a victorious manner, was, in the eyes of the disbelievers, something that only a misguided person could say. Therefore, Allah Almighty has already given the answer to what would come from their side, that you should say to them: My Lord knows best who has come with guidance and who is in clear misguidance, and soon this reality will become clear to you.

85-1 Or its recitation and its preaching and invitation have been made obligatory upon you.
85-2 That is, your birthplace Makkah, from where you were forced to leave. From Ibn Abbas ؓ, this is the interpretation narrated in Sahih Bukhari. Thus, eight years after the migration, Allah's promise was fulfilled and in 8 AH you ﷺ returned to Makkah victoriously. Some have taken "ma‘ad" to mean the Day of Resurrection. That is, on the Day of Resurrection, He will return you to Himself and will ask about the preaching of the message.
85-3 This is in response to the polytheists, who considered the Prophet ﷺ misguided because of his departure from their ancestral and traditional religion. It is said: My Lord knows best whether I am misguided, who has come with guidance from Allah, or you are, who are not accepting the guidance that has come from Allah?

85. O Prophet! Surely, the One (Allah) Who has made the Qur’an (its practice and propagation) [115] obligatory upon you will certainly bring you to the best outcome [116]. Say to them (the disbelievers): My Lord knows best who has come with guidance [117] and who is in clear error.

[115] That is, the responsibility of reciting the Quran to the people, teaching the Quran, acting upon it and showing it to others, and its propagation and preaching has been placed upon you.
[116]
The Different Meanings of Ma'ad:

Ma'ad means the place or time of returning. Since this word has a broad meaning, there is a difference of opinion in its interpretation. Most commentators have taken Ma'ad to mean the conquest of Makkah. According to their view, this verse was revealed during the migration from Makkah to Madinah. At that very time, you were given the glad tidings that you would return to this city of Makkah, and this meaning is also implied by ﴿وَاَنْتَ حِـۢلٌّ بِهٰذَا الْبَلَدِ﴾. Some people have taken Ma'ad to mean Paradise and all the promises Allah has made to you in this regard. Some have taken Ma'ad to mean the last moments of your life, when the entire Arabian Peninsula had come under the sway of Islam. And this superiority had not been achieved by anyone before you ﷺ, that at least politically, the whole of Arabia was under his control, and you were not only the political ruler of the entire Arabian Peninsula, but no religion except Islam remained in the Arabian Peninsula.
[117] Among the titles with which the disbelievers of Makkah used to address you ﷺ was also this: that you have become separated from the ancestral religion, and this was not said just once, but many times they repeated it. Therefore, this and similar verses were revealed at different times and in different surahs for your consolation.