Salam
The Prophets and Messengers all want their people to be guided. To sabotage their mission, Satan's casts regarding what they intend and wish. This includes how they wish for people to understand the Quran.
This is not the only verse though. It was an example, that God makes clear his signs, but they aren't clear to those with a disease in their hearts or have hard hearts, rather those people will for unclarity and ambiguity pertaining to the Rasool or Nabi's wish.
وَلَقَدْ أَخَذَ اللَّهُ مِيثَاقَ بَنِي إِسْرَائِيلَ وَبَعَثْنَا مِنْهُمُ اثْنَيْ عَشَرَ نَقِيبًا ۖ وَقَالَ اللَّهُ إِنِّي مَعَكُمْ ۖ لَئِنْ أَقَمْتُمُ الصَّلَاةَ وَآتَيْتُمُ الزَّكَاةَ وَآمَنْتُمْ بِرُسُلِي وَعَزَّرْتُمُوهُمْ وَأَقْرَضْتُمُ اللَّهَ قَرْضًا حَسَنًا لَأُكَفِّرَنَّ عَنْكُمْ سَيِّئَاتِكُمْ وَلَأُدْخِلَنَّكُمْ جَنَّاتٍ تَجْرِي مِنْ تَحْتِهَا الْأَنْهَارُ ۚ فَمَنْ كَفَرَ بَعْدَ ذَٰلِكَ مِنْكُمْ فَقَدْ ضَلَّ سَوَاءَ السَّبِيلِ | Certainly Allah took a covenant from the Children of Israel, and We raised from them twelve Captains. And Allah said, ‘I am with you! Surely, if you maintain the prayer and give the zakat and have faith in My apostles and support them and lend Allah a good loan, I will surely absolve you of your misdeeds, and I will surely admit you into gardens with streams running in them. But whoever of you disbelieves after that has certainly strayed from the right way.’ | Al-Maaida : 12
فَبِمَا نَقْضِهِمْ مِيثَاقَهُمْ لَعَنَّاهُمْ وَجَعَلْنَا قُلُوبَهُمْ قَاسِيَةً ۖ يُحَرِّفُونَ الْكَلِمَ عَنْ مَوَاضِعِهِ ۙ وَنَسُوا حَظًّا مِمَّا ذُكِّرُوا بِهِ ۚ وَلَا تَزَالُ تَطَّلِعُ عَلَىٰ خَائِنَةٍ مِنْهُمْ إِلَّا قَلِيلًا مِنْهُمْ ۖ فَاعْفُ عَنْهُمْ وَاصْفَحْ ۚ إِنَّ اللَّهَ يُحِبُّ الْمُحْسِنِينَ | Then, because of their breaking their covenant We cursed them and made their hearts hard: they pervert words from their place, and have neglected a part of what they were reminded. You will not cease to learn of some of their treachery, excepting a few of them. Yet excuse them and forbear. Indeed Allah loves the virtuous. | Al-Maaida : 13
So we see in the past, with Musa (a) covenant with his Twelve Successors (a) that as long as bani-Israel didn't enter that door of God that he wished them to enter in, they would not understand properly.
They neglect a portion and would distort God's words from their proper context.
Then later Allah (swt) reminds again:
لَقَدْ أَخَذْنَا مِيثَاقَ بَنِي إِسْرَائِيلَ وَأَرْسَلْنَا إِلَيْهِمْ رُسُلًا ۖ كُلَّمَا جَاءَهُمْ رَسُولٌ بِمَا لَا تَهْوَىٰ أَنْفُسُهُمْ فَرِيقًا كَذَّبُوا وَفَرِيقًا يَقْتُلُونَ | Certainly We took a covenant from the Children of Israel, and We sent apostles to them. Whenever an apostle brought them that which was not to their liking, they would deny a part of them, and a part they would slay. | Al-Maaida : 70
وَحَسِبُوا أَلَّا تَكُونَ فِتْنَةٌ فَعَمُوا وَصَمُّوا ثُمَّ تَابَ اللَّهُ عَلَيْهِمْ ثُمَّ عَمُوا وَصَمُّوا كَثِيرٌ مِنْهُمْ ۚ وَاللَّهُ بَصِيرٌ بِمَا يَعْمَلُونَ | They supposed there would be no testing, so they became blind and deaf. Thereafter Allah turned to them, yet [again] many of them became blind and deaf, and Allah watches what they do. | Al-Maaida : 71
So we see the covenant to Musa's (a) Successors, was such they denied them. And they took that accepting Musa (a), meant they would understand Torah and books of Prophets (a) and would not be blind to God's clear signs but this was not the case.
The verses of Surah Hajj, are speaking about all this too. Satan and his forces move against revelations and seek to make people misunderstand them especially after the founder.
The Quran talks about locks on the hearts that prevent people from properly reflecting and taking lesson from God's words. These are the knots blown upon and so sorcery of Witches and Satanic forces inwardly make people come to the falsehood outwardly.
It's the people with knowledge who see the Quran to be truth. Not the blind who might deceive themselves they believe in God and Quran and Mohammad (s) but then interpret the Quran per their desires and attribute God falsehood with no fear of God.
Allah (swt) wants Quran to contextualize itself. But he is warning those who break the covenant taken by him pertaining to the chosen ones, their hearts will harden and they will put words out of their context and move them out of their intended place in the book. This means they will not let Quran contextualize itself and it pertains to the covenant of Rasool (s).