Does the Qur'an call itself sufficient?

يَـٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوٓا۟ أَطِيعُوا۟ ٱللَّهَ وَأَطِيعُوا۟ ٱلرَّسُولَ وَأُو۟لِى ٱلْأَمْرِ مِنكُمْ ۖ فَإِن تَنَـٰزَعْتُمْ فِى شَىْءٍ فَرُدُّوهُ إِلَى ٱللَّهِ وَٱلرَّسُولِ إِن كُنتُمْ تُؤْمِنُونَ بِٱللَّهِ وَٱلْيَوْمِ ٱلْـَٔاخِرِ ۚ ذَٰلِكَ خَيْرٌ وَأَحْسَنُ تَأْوِيلًا

O ye who believe! Obey Allah, and obey the messenger and those of you who are in authority; and if ye have a dispute concerning any matter, refer it to Allah and the messenger if ye are (in truth) believers in Allah and the Last Day. That is better and more seemly in the end.

مَّن يُطِعِ ٱلرَّسُولَ فَقَدْ أَطَاعَ ٱللَّهَ ۖ وَمَن تَوَلَّىٰ فَمَآ أَرْسَلْنَـٰكَ عَلَيْهِمْ حَفِيظًا

Whoso obeyeth the messenger hath obeyed Allah, and whoso turneth away: We have not sent thee as a warder over them.

قُلْ أَىُّ شَىْءٍ أَكْبَرُ شَهَـٰدَةً ۖ قُلِ ٱللَّهُ ۖ شَهِيدٌۢ بَيْنِى وَبَيْنَكُمْ ۚ وَأُوحِىَ إِلَىَّ هَـٰذَا ٱلْقُرْءَانُ لِأُنذِرَكُم بِهِۦ وَمَنۢ بَلَغَ ۚ أَئِنَّكُمْ لَتَشْهَدُونَ أَنَّ مَعَ ٱللَّهِ ءَالِهَةً أُخْرَىٰ ۚ قُل لَّآ أَشْهَدُ ۚ قُلْ إِنَّمَا هُوَ إِلَـٰهٌ وَٰحِدٌ وَإِنَّنِى بَرِىٓءٌ مِّمَّا تُشْرِكُونَ

Say (O Muhammad): What thing is of most weight in testimony? Say: Allah is Witness between me and you. And this Qur'an hath been inspired in me, that I may warn therewith you and whomsoever it may reach. Do ye in sooth bear witness that there are gods beside Allah? Say: I bear no such witness. Say: He is only One Allah. Lo! I am innocent of that which ye associate (with Him).

وَمَا مِن دَآبَّةٍ فِى ٱلْأَرْضِ وَلَا طَـٰٓئِرٍ يَطِيرُ بِجَنَاحَيْهِ إِلَّآ أُمَمٌ أَمْثَالُكُم ۚ مَّا فَرَّطْنَا فِى ٱلْكِتَـٰبِ مِن شَىْءٍ ۚ ثُمَّ إِلَىٰ رَبِّهِمْ يُحْشَرُونَ

There is not an animal in the earth, nor a flying creature flying on two wings, but they are peoples like unto you. We have neglected nothing in the Book (of Our decrees). Then unto their Lord they will be gathered.

أَفَغَيْرَ ٱللَّهِ أَبْتَغِى حَكَمًا وَهُوَ ٱلَّذِىٓ أَنزَلَ إِلَيْكُمُ ٱلْكِتَـٰبَ مُفَصَّلًا ۚ وَٱلَّذِينَ ءَاتَيْنَـٰهُمُ ٱلْكِتَـٰبَ يَعْلَمُونَ أَنَّهُۥ مُنَزَّلٌ مِّن رَّبِّكَ بِٱلْحَقِّ ۖ فَلَا تَكُونَنَّ مِنَ ٱلْمُمْتَرِينَ

Shall I seek other than Allah for judge, when He it is Who hath revealed unto you (this) Scripture, fully explained? Those unto whom We gave the Scripture (aforetime) know that it is revealed from thy Lord in truth. So be not thou (O Muhammad) of the waverers.

وَتَمَّتْ كَلِمَتُ رَبِّكَ صِدْقًا وَعَدْلًا ۚ لَّا مُبَدِّلَ لِكَلِمَـٰتِهِۦ ۚ وَهُوَ ٱلسَّمِيعُ ٱلْعَلِيمُ

Perfected is the Word of thy Lord in truth and justice. There is naught that can change His words. He is the Hearer, the Knower.

ٱتَّبِعُوا۟ مَآ أُنزِلَ إِلَيْكُم مِّن رَّبِّكُمْ وَلَا تَتَّبِعُوا۟ مِن دُونِهِۦٓ أَوْلِيَآءَ ۗ قَلِيلًا مَّا تَذَكَّرُونَ

(Saying): Follow that which is sent down unto you from your Lord, and follow no protecting friends beside Him. Little do ye recollect!

لَقَدْ كَانَ فِى قَصَصِهِمْ عِبْرَةٌ لِّأُو۟لِى ٱلْأَلْبَـٰبِ ۗ مَا كَانَ حَدِيثًا يُفْتَرَىٰ وَلَـٰكِن تَصْدِيقَ ٱلَّذِى بَيْنَ يَدَيْهِ وَتَفْصِيلَ كُلِّ شَىْءٍ وَهُدًى وَرَحْمَةً لِّقَوْمٍ يُؤْمِنُونَ

In their history verily there is a lesson for men of understanding. It is no invented story but a confirmation of the existing (Scripture) and a detailed explanation of everything, and a guidance and a mercy for folk who believe.

بِٱلْبَيِّنَـٰتِ وَٱلزُّبُرِ ۗ وَأَنزَلْنَآ إِلَيْكَ ٱلذِّكْرَ لِتُبَيِّنَ لِلنَّاسِ مَا نُزِّلَ إِلَيْهِمْ وَلَعَلَّهُمْ يَتَفَكَّرُونَ

With clear proofs and writings; and We have revealed unto thee the Remembrance that thou mayst explain to mankind that which hath been revealed for them, and that haply they may reflect.

وَيَوْمَ نَبْعَثُ فِى كُلِّ أُمَّةٍ شَهِيدًا عَلَيْهِم مِّنْ أَنفُسِهِمْ ۖ وَجِئْنَا بِكَ شَهِيدًا عَلَىٰ هَـٰٓؤُلَآءِ ۚ وَنَزَّلْنَا عَلَيْكَ ٱلْكِتَـٰبَ تِبْيَـٰنًا لِّكُلِّ شَىْءٍ وَهُدًى وَرَحْمَةً وَبُشْرَىٰ لِلْمُسْلِمِينَ

And (bethink you of) the day when We raise in every nation a witness against them of their own folk, and We bring thee (Muhammad) as a witness against these. And We reveal the Scripture unto thee as an exposition of all things, and a guidance and a mercy and good tidings for those who have surrendered (to Allah).

وَقَالَ ٱلرَّسُولُ يَـٰرَبِّ إِنَّ قَوْمِى ٱتَّخَذُوا۟ هَـٰذَا ٱلْقُرْءَانَ مَهْجُورًا

And the messenger saith: O my Lord! Lo! mine own folk make this Qur'an of no account.

تِلْكَ ءَايَـٰتُ ٱللَّهِ نَتْلُوهَا عَلَيْكَ بِٱلْحَقِّ ۖ فَبِأَىِّ حَدِيثٍۭ بَعْدَ ٱللَّهِ وَءَايَـٰتِهِۦ يُؤْمِنُونَ

These are the portents of Allah which We recite unto thee (Muhammad) with truth. Then in what fact, after Allah and His portents, will they believe?