If Allah willed, He could take away the Qur'an

Allah mentions the blessing and great bounty that He has bestowed upon His servant and Messenger Muhammad by revealing to Him the Noble Qur'an to which falsehood cannot come, from before it or behind it, (it is) sent down by the All-Wise, Worthy of all praise. Ibn Mas`ud said, "A red wind will come to the people, meaning at the end of time, from the direction of Syria, and there will be nothing left in a man's Mushaf (copy of the Qur'an) or in his heart, not even one Ayah." Then Ibn Mas`ud recited:

وَلَئِن شِئْنَا لَنَذْهَبَنَّ بِالَّذِى أَوْحَيْنَا إِلَيْكَ

We can now move to verse 86: وَلَئِن شِئْنَا لَنَذْهَبَنَّ (And if We so will, We will surely take away...). It will be recollected that, in the previous verse (85), by giving an answer to the question about Ruh as true to the measure of its necessity, the underlying effort to find out the reality of the Ruh was blocked and it was declared that man's knowledge, no matter how much, still remains relatively insignificant in terms of the great span of the ultimate reality of things. Therefore, getting entangled with unnecessary debates and investigations is a waste of precious time. The present verse: وَلَئِن شِئْنَا (And if We so will) indicates that the sum total of whatever knowledge human beings have been given, even that is no private property of theirs. Allah Ta` ala can, if He so wills, take away that too. Therefore, they should be grateful to Allah for whatever of knowledge they have and stay away from wasting time in redundant and unnecessary investigations - specially when pure investigation is just not the objective, instead, testing others or belittling them is. If one did that, it is not out of the realm of possibility that this crookedness may result in all that one has in the name of knowledge taken away in toto. The address in this verse is, though, to the Holy Prophet ﷺ ، but the purpose is to really make his followers listen and get the message - when even the knowledge of the Rasul of Allah ﷺ is not within his exclusive power and control, not much can be said about others!