The Qur'an is the True, Inimitable Word of Allah and It is a Miracle
The Qur'an has a miraculous nature that cannot be imitated. No one can produce anything similar to the Qur'an, nor ten Surahs or even one Surah like it. The eloquence, clarity, precision and grace of the Qur'an cannot be but from Allah. The great and abundant principles and meanings within the Qur'an -- which are of great benefit in this world and for the Hereafter -- cannot be but from Allah. There is nothing like His High Self and Attributes or like His sayings and actions. Therefore His Words are not like the words of His creatures. This is why Allah said:
وَمَا كَانَ هَـذَا الْقُرْءَانُ أَن يُفْتَرَى مِن دُونِ اللَّهِ
(And this Qur'an is not such as could ever be produced by other than Allah) meaning, a book like this cannot be but from Allah. This is not similar to the speech uttered by humans.
وَلَـكِن تَصْدِيقَ الَّذِى بَيْنَ يَدَيْهِ
(but it is a confirmation of (the revelation) which was before it,) Such as previous revelations and Books. The Qur'an confirms these books and is a witness to them. It shows the changes, perversions and corruption that have taken place within these Books. Then Allah said,
وَتَفْصِيلَ الْكِتَابِ لاَ رَيْبَ فِيهِ مِن رَّبِّ الْعَـلَمِينَ
(and a full explanation of the Book -- wherein there is no doubt -- from the Lord of all that exists.) That is, fully and truly explaining and detailing the rules and the lawful and the unlawful. With this complete and more than sufficient explanation, the Qur'an leaves no doubt that it is from Allah, the Lord of all that exists. Allah says,
أَمْ يَقُولُونَ افْتَرَاهُ قُلْ فَأْتُواْ بِسُورَةٍ مِّثْلِهِ وَادْعُواْ مَنِ اسْتَطَعْتُمْ مِّن دُونِ اللَّهِ إِن كُنتُمْ صَـدِقِينَ
(Or do they say: "He has forged it" Say: "Bring then a Surah like unto it, and call upon whomsoever you can besides Allah, if you are truthful!") If you argue, claim and doubt whether this is from Allah then you uttered a lie and blasphemy, and you say it is from Muhammad -- Muhammad , however is a man like you, and since he came as you claim with this Qur'an -- then you produce a Surah like one of its Surahs. Produce something of the same nature and seek help and support with all the power you have from humans and Jinns. This is the third stage, Allah challenged them and called them to produce a counterpart of the Qur'an if they were truthful in their claim that it was simply from Muhammad . Allah even suggested that they seek help from anyone they chose. But He told them that they would not be able to do it. They would have no way of doing so. Allah said:
قُل لَّئِنِ اجْتَمَعَتِ الإِنسُ وَالْجِنُّ عَلَى أَن يَأْتُواْ بِمِثْلِ هَـذَا الْقُرْءَانِ لاَ يَأْتُونَ بِمِثْلِهِ وَلَوْ كَانَ بَعْضُهُمْ لِبَعْضٍ ظَهِيرًا
(Say: "If the mankind and the Jinn were together to produce the like of this Qur'an, they could not produce the like thereof, even if they helped one another.") 17:88 Then He reduced the number for them to ten Surahs similar to it, in the beginning of Surah Hud, Allah said:
أَمْ يَقُولُونَ افْتَرَاهُ قُلْ فَأْتُواْ بِعَشْرِ سُوَرٍ مِّثْلِهِ مُفْتَرَيَاتٍ وَادْعُواْ مَنِ اسْتَطَعْتُمْ مِّن دُونِ اللَّهِ إِن كُنتُمْ صَـدِقِينَ
(Or they say, "He forged it." Say: "Bring you then ten forged Surah like unto it, and call whomsoever you can, other than Allah, if you speak the truth!")11:13 In this Surah He went even further to challenge them to produce only one Surah like unto the Qur'an. So He said:
أَمْ يَقُولُونَ افْتَرَاهُ قُلْ فَأْتُواْ بِسُورَةٍ مِّثْلِهِ وَادْعُواْ مَنِ اسْتَطَعْتُمْ مِّن دُونِ اللَّهِ إِن كُنتُمْ صَـدِقِينَ
(Or do they say: "He has forged it" Say: "Bring then a Surah like unto it, and call upon whomsoever you can besides Allah, if you are truthful!") 10:38 He also challenged them in Surat Al-Baqarah, a Madinite Surah, to produce one Surah similar to it. He stated in that Surah that they would never be capable of doing so, saying:
فَإِن لَّمْ تَفْعَلُواْ وَلَن تَفْعَلُواْ فَاتَّقُواْ النَّارَ
(But if you do it not, and you can never do it, then fear the Fire (Hell).)2:24 It should be noted here that eloquence was a part of the nature and character of the Arabs. Arabic poetry including Al-Mu`allaqat -- the oldest complete collection of the most eloquent ancient Arabic poems -- was considered to be the best in the literary arts. However Allah sent down to them something whose style none were familiar with, and no one is equal in stature to imitate. So those who believed among them, believed because of what they knew and felt in the Book, including its beauty, elegance, benefit, and fluency. They became the most knowledgeable of the Qur'an and its best in adhering to it. The same thing happened to the magicians during Fir`awn's time. They were knowledgeable of the arts of sorcery, however, when Musa performed his miracles, they knew that it must have come through someone that was supported and guided by Allah. They knew that no human could perform such acts without the permission of Allah. Similarly, `Isa was sent at the time of scholarly medicine and during the advancement in the treatment of patients. He healed the blind, lepers and raised the dead to life by Allah's leave. What `Isa was able to do was such that no form of treatment or medicine could reproduce. As a result, those who believed in him knew that he was Allah's servant and His Messenger. Similarly, in the Sahih, Allah's Messenger ﷺ said,
«مَا مِنْ نَبِيَ مِنَ الْأَنْبِيَاءِ إِلَّا وَقَدْ أُوتِيَ مِنَ الْآيَاتِ مَا آمَنَ عَلَى مِثْلِهِ الْبَشَرُ، وَإِنَّمَا كَانَ الَّذِي أُوتِيتُهُ وَحْيًا أَوْحَاهُ اللهُ إِلَيَّ فَأَرْجُو أَنْ أَكُونَ أَكْثَرَهُمْ تَابِعًا»
(There was never a Prophet but he was given signs by which the people would recognize him, and that which I was given is revelation that Allah revealed, so I hope that I will have the most followers among them.) Allah then said:
بَلْ كَذَّبُواْ بِمَا لَمْ يُحِيطُواْ بِعِلْمِهِ وَلَمَّا يَأْتِهِمْ تَأْوِيلُهُ
(Nay, they have belied the knowledge whereof they could not comprehend and what has not yet been fulfilled. ) They did not believe in the Qur'an and they have not yet grasped it or comprehended it.
وَلَمَّا يَأْتِهِمْ تَأْوِيلُهُ
(And what has not yet been fulfilled.) They have not attained the guidance and the true religion. So they belied it out of ignorance and foolishness.
كَذَلِكَ كَذَّبَ الَّذِينَ مِن قَبْلِهِمْ
(Those before them did belie.) meaning, the past nations,
فَانظُرْ كَيْفَ كَانَ عَـقِبَةُ الظَّـلِمِينَ
(Then see what was the end of the wrongdoers!) Look at how we Destroyed them because they denied Our Messengers in their wickedness, pride, stubbornness and ignorance. So beware you who deny the message that the same end will befall you. Allah's statement,
وَمِنهُمْ مَّن يُؤْمِنُ بِهِ
(And of them there are some who believe therein;) means that among those you were sent to, O Muhammad, are people who will believe in this Qur'an, follow you and benefit from what has been sent to you.
وَمِنْهُمْ مَّن لاَّ يُؤْمِنُ بِهِ
(and of them there are some who believe not therein,) but dies as a disbeliever and will be resurrected as such.
وَرَبُّكَ أَعْلَمُ بِالْمُفْسِدِينَ
(And your Lord is All-Aware of the mischief makers. ) He best knows those who deserve guidance, so He guides them, and those who deserve to go astray, He allows to go astray. Allah is, however, the Just who is never unjust. He gives everyone what they deserve. All Glory is His, the Exalted. There is no God but He.