Allah says;

لَا تُحَرِّكْ بِهِ لِسَانَكَ لِتَعْجَلَ بِهِ (16) إِنَّ عَلَيْنَا جَمْعَهُ وَقُرْآنَهُ (17) فَإِذَا قَرَأْنَاهُ فَاتَّبِعْ قُرْآنَهُ (18) ثُمَّ إِنَّ عَلَيْنَا بَيَانَهُ (19)” سورة القيامة”

“move not your tongue with it, (O Muhammad), to hasten with recitation of the Quran. Indeed, upon Us is its collection (in your heart) and (to make possible) its recitation. So, when We have recited it (through Gabriel), then follow its recitation. Then upon Us is its clarification (to you).”  surrat Al-Qiyama.

Allah `SWT` ensure that he will preserve the Quran to the Day of Resurrection until it will be rose from the earth and no one of the creatures on earth has the grace on this, as well as no one has the ability to change any single letter from due to the preservation of Allah ‘SWT’ to it as it is the last revealed Book ever. 

The Book that is has the argument against people in the day of resurrection.

Allah ‘SWT’ makes it easy for the believers to memorize and understand it, generation after generation.

The reason behind the revelation of the verse” move not your tongue with it, (O Muhammad), to hasten with recitation of the Quran” is that the prophet (peace be upon Him) was keen on memorizing the Quran and studying it to not to forget it, as the angel ‘Gabriel’ sent down on the prophet to recite the Quran in front of him.

The Prophet (peace and blessings of Allah be upon him) felt the intensity when the revelation was revealed to him so, he hastened to recite the Quran during the revelation, not to forget what was revealed to him.

The Companions saw the difficulty of the matter in the face of the Prophet and his sweat when the angel came down to him

So, reading it and revising it what was revealed to him a little while during the revelation of revelation makes it more difficult

Therefore, Allah says (interpretation of the meaning): “Do not move your tongue by reciting the Quran before the angel finishes reading it. We have to collect the Quran in your chest and heart. We will make you read in right way, but if you recite it (O Muhammad) so, follow the rules of permissible and forbidden and follow the recommendations and ways of worship that revealed into it. As it is clear in the verse “Then upon Us is its clarification (to you)”.

Allah ‘SWT’ tell His Prophet (peace and blessings of Allah be upon him) that Allah has a clear statement about the matters of faith, worship, and transactions for you so that you can understand it and inform people with it as Allah wanted. This indicates that Allah taught the Prophet the meaning of the Quran as he wanted to teach people all things about their religion properly. So that, if the companions didn’t understand anything in the Quran, they ask the prophet about it to be clear to them

In conclusion, we show you that the Quran is a preserved Book and there is no single way to be distorted until the Day of Resurrection

No matter how the demons or humans do, if you memorized it or studied its meanings, you have to know that Allah has chosen you for a great honor for Allah to choose him, but the honor in the world and the rest; Because Allah chooses only those who believe.

We Ask Allah to give us the sincerity in memorizing, reciting it and be our deed based on every rule in the Quran.