Quran is the remarks and language of God

God considered several responsibilities for the messenger of God and lead him toward them. One of them is that he recites the verses of Quran for people properly. Moreover, he interprets and explains the verses of Quran for people. Thirdly, he explains the way of acting its rules and purifies the soul of people through doing good actions.
Quran states
وَ الَّذِي بَعَثَ فِي الْأُمِّيِّينَ رَسُولًا مِّنْهُمْ يَتْلُو عَلَيْهِمْ آيَاتِهِ وَيُزَكِّيهِمْ وَيُعَلِّمُهُمُ الْكِتَابَ وَالْحِكْمَةَ وَإِن كَانُوا مِن قَبْلُ لَفِي ضَلَالٍ مُّبِينٍ
It is He Who has sent amongst the Unlettered a messenger from among themselves, to rehearse to them His Signs, to sanctify them, and to instruct them in Scripture and Wisdom,- although they had been, before, in manifest error.
وَأَنْ أَتْلُوَ الْقُرْآنَ ۖ فَمَنِ اهْتَدَىٰ فَإِنَّمَا يَهْتَدِي لِنَفْسِهِ ۖ وَمَن ضَلَّ فَقُلْ إِنَّمَا أَنَا مِنَ الْمُنذِرِينَ
And to rehearse the Qur´an: and if any accept guidance, they do it for the good.
بِالْبَيِّنَاتِ وَالزُّبُرِ ۗ وَأَنزَلْنَا إِلَيْكَ الذِّكْرَ لِتُبَيِّنَ لِلنَّاسِ مَا نُزِّلَ إِلَيْهِمْ وَلَعَلَّهُمْ يَتَفَكَّرُونَ
(We sent them) with Clear Signs and Books of dark prophecies; and We have sent down unto thee (also) the Message; that thou mayest explain clearly to men what is sent for them, and that they may give thought.
وَ الَّذِي بَعَثَ فِي الْأُمِّيِّينَ رَسُولًا مِّنْهُمْ يَتْلُو عَلَيْهِمْ آيَاتِهِ وَيُزَكِّيهِمْ وَيُعَلِّمُهُمُ الْكِتَابَ وَالْحِكْمَةَ وَإِن كَانُوا مِن قَبْلُ لَفِي ضَلَالٍ مُّبِينٍ
It is He Who has sent amongst the Unlettered a messenger from among themselves, to rehearse to them His Signs, to sanctify them, and to instruct them in Scripture and Wisdom,- although they had been, before, in manifest error.
Quran states that the messenger of God admonishes people to do good actions;
فَذَكِّرْ إِنَّمَا أَنتَ مُذَكِّرٌ
Therefore do thou give admonition, for thou art one to admonish.
God introduces the messenger of God as a pattern for human;
لَّقَدْ كَانَ لَكُمْ فِي رَسُولِ اللَّهِ أُسْوَةٌ حَسَنَةٌ لِّمَن كَانَ يَرْجُو اللَّهَ وَالْيَوْمَ الْآخِرَ وَذَكَرَ اللَّهَ كَثِيرًا
Ye have indeed in the Messenger of Allah a beautiful pattern (of conduct) for any one whose hope is in Allah and the Final Day, and who engages much in the Praise of Allah.
Quran states about the mission of the prophet
إِنَّمَا أُمِرْتُ أَنْ أَعْبُدَ رَبَّ هَٰذِهِ الْبَلْدَةِ الَّذِي حَرَّمَهَا وَلَهُ كُلُّ شَيْءٍ ۖ وَأُمِرْتُ أَنْ أَكُونَ مِنَ الْمُسْلِمِينَ
For me, I have been commanded to serve the Lord of this city, Him Who has sanctified it and to Whom (belong) all things: and I am commanded to be of those who bow in Islam to Allah´s Will.
وَأَنْ أَتْلُوَ الْقُرْآنَ ۖ فَمَنِ اهْتَدَىٰ فَإِنَّمَا يَهْتَدِي لِنَفْسِهِ ۖ وَمَن ضَلَّ فَقُلْ إِنَّمَا أَنَا مِنَ الْمُنذِرِينَ
And to rehearse the Qur´an: and if any accept guidance, they do it for the good of their own souls, and if any stray, say: "I am only a Warner.
Quran states
تِلْكَ آيَاتُ اللَّهِ نَتْلُوهَا عَلَيْكَ بِالْحَقِّ ۗ وَمَا اللَّهُ يُرِيدُ ظُلْمًا لِّلْعَالَمِينَ
These are the Signs of Allah: We rehearse them to thee in Truth: And Allah means no injustice to any of His creatures.
Quran states about the preservation of the verses of Quran;
وَمَا نَتَنَزَّلُ إِلَّا بِأَمْرِ رَبِّكَ ۖ لَهُ مَا بَيْنَ أَيْدِينَا وَمَا خَلْفَنَا وَمَا بَيْنَ ذَٰلِكَ ۚ وَمَا كَانَ رَبُّكَ نَسِيًّا
(The angels say:) "We descend not but by command of thy Lord: to Him belongeth what is before us and what is behind us, and what is between: and thy Lord never doth forget.
لَا يَسْبِقُونَهُ بِالْقَوْلِ وَهُم بِأَمْرِهِ يَعْمَلُونَ
. They speak not before He speaks, and they act (in all things) by His Command
مطَاعٍ ثَمَّ أَمِينٍ
With authority there, (and) faithful to his trust.
وَمَا هُوَ عَلَى الْغَيْبِ بِضَنِينٍ
Neither doth he withhold grudgingly a knowledge of the Unseen.
God states to the messenger of God (peace of Allah be upon him and his descendants)

یس
Ya Sin.
وَالْقُرْآنِ الْحَكِيمِ
.By the Qur´an, full of Wisdom
إِنَّكَ لَمِنَ الْمُرْسَلِينَ
.Thou art indeed one of the messengers
عَلَىٰ صِرَاطٍ مُّسْتَقِيمٍ
On a Straight Way.
حم
. Ha-Mim
وَالْكِتَابِ الْمُبِينِ
. By the Book that makes things clear
Quran states
إِنَّا جَعَلْنَاهُ قُرْآنًا عَرَبِيًّا لَّعَلَّكُمْ تَعْقِلُونَ
We have made it a Qur´an in Arabic, that ye may be able to understand (and learn wisdom).
وَإِنَّهُ فِي أُمِّ الْكِتَابِ لَدَيْنَا لَعَلِيٌّ حَكِيمٌ
And verily, it is in the Mother of the Book, in Our Presence, high (in dignity), full of wisdom.
وَلَقَدْ نَعْلَمُ أَنَّهُمْ يَقُولُونَ إِنَّمَا يُعَلِّمُهُ بَشَرٌ ۗ لِّسَانُ الَّذِي يُلْحِدُونَ إِلَيْهِ أَعْجَمِيٌّ وَهَٰذَا لِسَانٌ عَرَبِيٌّ مُّبِينٌ
We know indeed that they say, "It is a man that teaches him." The tongue of him they wickedly point to is notably foreign, while this is Arabic, pure and clear.
وَمَا كَانَ هَٰذَا الْقُرْآنُ أَن يُفْتَرَىٰ مِن دُونِ اللَّهِ وَلَٰكِن تَصْدِيقَ الَّذِي بَيْنَ يَدَيْهِ وَتَفْصِيلَ الْكِتَابِ لَا رَيْبَ فِيهِ مِن رَّبِّ الْعَالَمِينَ
This Qur´an is not such as can be produced by other than Allah; on the contrary it is a confirmation of (revelations) that went before it, and a fuller explanation of the Book - wherein there is no doubt - from the Lord of the worlds.
فَلَمْ تَقْتُلُوهُمْ وَلَٰكِنَّ اللَّهَ قَتَلَهُمْ ۚ وَمَا رَمَيْتَ إِذْ رَمَيْتَ وَلَٰكِنَّ اللَّهَ رَمَىٰ ۚ وَلِيُبْلِيَ الْمُؤْمِنِينَ مِنْهُ بَلَاءً حَسَنًا ۚ إِنَّ اللَّهَ سَمِيعٌ عَلِيمٌ
It is not ye who slew them; it was Allah: when thou threwest (a handful of dust), it was not thy act, but Allah´s: in order that He might test the Believers by a gracious trial from Himself: for Allah is He Who heareth and knoweth (all things).
إِنْ أَحَدٌ مِّنَ الْمُشْرِكِينَ اسْتَجَارَكَ فَأَجِرْهُ حَتَّىٰ يَسْمَعَ كَلَامَ اللَّهِ ثُمَّ أَبْلِغْهُ مَأْمَنَهُ ۚ ذَٰلِكَ بِأَنَّهُمْ قَوْمٌ لَّا يَعْلَمُونَ
If one amongst the Pagans ask thee for asylum, grant it to him, so that he may hear the word of Allah; and then escort him to where he can be secure. That is because they are men without knowledge.
لِنَجْعَلَهَا لَكُمْ تَذْكِرَةً وَتَعِيَهَا أُذُنٌ وَاعِيَةٌ
That We might make it a Message unto you, and that ears (that should hear the tale and) retain its memory should bear its (lessons) in remembrance.
قُلْ فَلِلَّهِ الْحُجَّةُ الْبَالِغَةُ ۖ فَلَوْ شَاءَ لَهَدَاكُمْ أَجْمَعِينَ
Say: "With Allah is the argument that reaches home: if it had been His will, He could indeed have guided you all.
سُبْحَانَ الَّذِي أَسْرَىٰ بِعَبْدِهِ لَيْلًا مِّنَ الْمَسْجِدِ الْحَرَامِ إِلَى الْمَسْجِدِ الْأَقْصَى الَّذِي بَارَكْنَا حَوْلَهُ لِنُرِيَهُ مِنْ آيَاتِنَا ۚ إِنَّهُ هُوَ السَّمِيعُ الْبَصِيرُ
Glory to (Allah) Who did take His servant for a Journey by night from the Sacred Mosque to the farthest Mosque, whose precincts We did bless,- in order that We might show him some of Our Signs: for He is the One Who heareth and seeth (all things).
Quran states
فَلَمْ تَقْتُلُوهُمْ وَلَٰكِنَّ اللَّهَ قَتَلَهُمْ ۚ وَمَا رَمَيْتَ إِذْ رَمَيْتَ وَلَٰكِنَّ اللَّهَ رَمَىٰ ۚ وَلِيُبْلِيَ الْمُؤْمِنِينَ مِنْهُ بَلَاءً حَسَنًا ۚ إِنَّ اللَّهَ سَمِيعٌ عَلِيمٌ
It is not ye who slew them; it was Allah: when thou threwest (a handful of dust), it was not thy act, but Allah´s: in order that He might test the Believers by a gracious trial from Himself: for Allah is He Who heareth and knoweth (all things).
قَاتِلُوهُمْ يُعَذِّبْهُمُ اللَّهُ بِأَيْدِيكُمْ وَيُخْزِهِمْ وَيَنصُرْكُمْ عَلَيْهِمْ وَيَشْفِ صُدُورَ قَوْمٍ مُّؤْمِنِينَ
Fight them, and Allah will punish them by your hands, cover them with shame, help you (to victory) over them, heal the breasts of Believers.
The recitation of the verses of Quran that is heard from devout persons is same talking to God as Quran states
وَإِذَا قُرِئَ الْقُرْآنُ فَاسْتَمِعُوا لَهُ وَأَنصِتُوا لَعَلَّكُمْ تُرْحَمُونَ
When the Qur´an is read, listen to it with attention, and hold your peace: that ye may receive Mercy.
وَلَوْ جَعَلْنَاهُ قُرْآنًا أَعْجَمِيًّا لَّقَالُوا لَوْلَا فُصِّلَتْ آيَاتُهُ ۖ أَأَعْجَمِيٌّ وَعَرَبِيٌّ ۗ قُلْ هُوَ لِلَّذِينَ آمَنُوا هُدًى وَشِفَاءٌ ۖ وَالَّذِينَ لَا يُؤْمِنُونَ فِي آذَانِهِمْ وَقْرٌ وَهُوَ عَلَيْهِمْ عَمًى ۚ أُولَٰئِكَ يُنَادَوْنَ مِن مَّكَانٍ بَعِيدٍ
Had We sent this as a Qur´an (in the language) other than Arabic, they would have said: "Why are not its verses explained in detail? What! (a Book) not in Arabic and (a Messenger an Arab?" Say: "It is a Guide and a Healing to those who believe; and for those who believe not, there is a deafness in their ears, and it is blindness in their (eyes): They are (as it were) being called from a place far distant.
Quran is the existence of God and the prophet annunciates all of the blessings of God to human. Quran is not only duty, but it is also the specific blessings of God. Quran states
وَلَا يَحْسَبَنَّ الَّذِينَ يَبْخَلُونَ بِمَا آتَاهُمُ اللَّهُ مِن فَضْلِهِ هُوَ خَيْرًا لَّهُم ۖ بَلْ هُوَ شَرٌّ لَّهُمْ ۖ سَيُطَوَّقُونَ مَا بَخِلُوا بِهِ يَوْمَ الْقِيَامَةِ ۗ وَلِلَّهِ مِيرَاثُ السَّمَاوَاتِ وَالْأَرْضِ ۗ وَاللَّهُ بِمَا تَعْمَلُونَ خَبِيرٌ
And let not those who covetously withhold of the gifts which Allah Hath given them of His Grace, think that it is good for them: Nay, it will be the worse for them: soon shall the things which they covetously withheld be tied to their necks Like a twisted collar, on the Day of Judgment. To Allah belongs the heritage of the heavens and the earth; and Allah is well-acquainted with all that ye do.
أَوْ كَالَّذِي مَرَّ عَلَىٰ قَرْيَةٍ وَهِيَ خَاوِيَةٌ عَلَىٰ عُرُوشِهَا قَالَ أَنَّىٰ يُحْيِي هَٰذِهِ اللَّهُ بَعْدَ مَوْتِهَا ۖ فَأَمَاتَهُ اللَّهُ مِائَةَ عَامٍ ثُمَّ بَعَثَهُ ۖ قَالَ كَمْ لَبِثْتَ ۖ قَالَ لَبِثْتُ يَوْمًا أَوْ بَعْضَ يَوْمٍ ۖ قَالَ بَل لَّبِثْتَ مِائَةَ عَامٍ فَانظُرْ إِلَىٰ طَعَامِكَ وَشَرَابِكَ لَمْ يَتَسَنَّهْ ۖ وَانظُرْ إِلَىٰ حِمَارِكَ وَلِنَجْعَلَكَ آيَةً لِّلنَّاسِ ۖ وَانظُرْ إِلَى الْعِظَامِ كَيْفَ نُنشِزُهَا ثُمَّ نَكْسُوهَا لَحْمًا ۚ فَلَمَّا تَبَيَّنَ لَهُ قَالَ أَعْلَمُ أَنَّ اللَّهَ عَلَىٰ كُلِّ شَيْءٍ قَدِيرٌ
Or (take) the similitude of one who passed by a hamlet, all in ruins to its roofs. He said: "Oh! how shall Allah bring it (ever) to life, after (this) its death?" but Allah caused him to die for a hundred years, then raised him up (again). He said: "How long didst thou tarry (thus)?" He said: (Perhaps) a day or part of a day." He said: "Nay, thou hast tarried thus a hundred years; but look at thy food and thy drink; they show no signs of age; and look at thy donkey: And that We may make of thee a sign unto the people, Look further at the bones, how We bring them together and clothe them with flesh." When this was shown clearly to him, he said: "I know that Allah hath power over all things''.
يَا أَيُّهَا الَّذِينَ آمَنُوا لَا تُبْطِلُوا صَدَقَاتِكُم بِالْمَنِّ وَالْأَذَىٰ كَالَّذِي يُنفِقُ مَالَهُ رِئَاءَ النَّاسِ وَلَا يُؤْمِنُ بِاللَّهِ وَالْيَوْمِ الْآخِرِ ۖ فَمَثَلُهُ كَمَثَلِ صَفْوَانٍ عَلَيْهِ تُرَابٌ فَأَصَابَهُ وَابِلٌ فَتَرَكَهُ صَلْدًا ۖ لَّا يَقْدِرُونَ عَلَىٰ شَيْءٍ مِّمَّا كَسَبُوا ۗ وَاللَّهُ لَا يَهْدِي الْقَوْمَ الْكَافِرِينَ
O ye who believe! cancel not your charity by reminders of your generosity or by injury,- like those who spend their substance to be seen of men, but believe neither in Allah nor in the Last Day. They are in parable like a hard, barren rock, on which is a little soil: on it falls heavy rain, which leaves it (Just) a bare stone. They will be able to do nothing with aught they have earned. And Allah guideth not those who reject faith.

أَنتُمْ هَٰؤُلَاءِ تَقْتُلُونَ أَنفُسَكُمْ وَتُخْرِجُونَ فَرِيقًا مِّنكُم مِّن دِيَارِهِمْ تَظَاهَرُونَ عَلَيْهِم بِالْإِثْمِ وَالْعُدْوَانِ وَإِن يَأْتُوكُمْ أُسَارَىٰ تُفَادُوهُمْ وَهُوَ مُحَرَّمٌ عَلَيْكُمْ إِخْرَاجُهُمْ ۚ أَفَتُؤْمِنُونَ بِبَعْضِ الْكِتَابِ وَتَكْفُرُونَ بِبَعْضٍ ۚ فَمَا جَزَاءُ مَن يَفْعَلُ ذَٰلِكَ مِنكُمْ إِلَّا خِزْيٌ فِي الْحَيَاةِ الدُّنْيَا ۖ وَيَوْمَ الْقِيَامَةِ يُرَدُّونَ إِلَىٰ أَشَدِّ الْعَذَابِ ۗ وَمَا اللَّهُ بِغَافِلٍ عَمَّا تَعْمَلُونَ
After this it is ye, the same people, who slay among yourselves, and banish a party of you from their homes; assist (Their enemies) against them, in guilt and rancour; and if they come to you as captives, ye ransom them, though it was not lawful for you to banish them. Then is it only a part of the Book that ye believe in, and do ye reject the rest? but what is the reward for those among you who behave like this but disgrace in this life?- and on the Day of Judgment they shall be consigned to the most grievous penalty. For Allah is not unmindful of what ye do.