Allah Almighty is the all-knowing all-wise creator. He has considered a unique way of perfection for every creature and then guided it to reach its excellence (20:50). Human beings, as autonomous creatures, are in real need of divine guidance to know how to live a perfect and purposeful life. According to Islamic beliefs, the Quran is the divine revelation to Prophet Muhammad PBUH&HP that contains necessary guidelines for human beings: "As We sent to you an Apostle from among yourselves, who recites to you Our signs, and purifies you, and teaches you the Book and wisdom, and teaches you what you did not know." (2:151). The question is that, is the Quran Allah's words? Let's see why the answer is: Yes. 

1. The Holy Quran and the Prophetic Narrations are Not of the Same Style

If the Quran was Prophet Muhammad's PBUH&HP words, his PBUH&HP narrations should have been of the same eloquence and beauty of the Quran. But that's not the case. The Quran is unique in style, expression system, and arrangement. And that's why no one has been able to bring even a chapter (Surah) similar to that of the Quran. As the Quran says: "And if you are in doubt concerning what We have sent down to Our servant, then bring a Surah like it, and invoke your helpers besides Allah, should you be truthful." (2:23). Although the prophetic narrations are articulate and eloquent, some of them have been imitated and distorted, unlike the Quran [1].

2. Prophet Muhammad PBUH&HP Never Claimed These Words to Be His

If the Quran were Prophet Muhammad's PBUH & HP words, it would have been logical for him to claim that these eloquent words were his. Consequently, he could have promoted his position, fascinated his opposers, and gathered more followers. But, he never intended to be considered and praised as a superior power. On the contrary, in one instance, someone came to him and was uneasy because of his magnificence and grandeur, he said: "Calm down! I am not a king" [2]. 

3. The Objection of Prophet Muhammad's PBUH&HP Oppposers Were not Answered Immediately  

In some of the Quranic verses, the objections and disagreements of Prophet's PBUH&HP opposers are answered. If the Quran was Prophet Muhammad's PBUH&HP words, all these verses should have been quickly revealed right after an objection was raised, or when he was insulted or oppressed. But, this was not always the case [1]. 

For example, the Qiblah at the time of Prophet Muhammad PBUH&HP was originally the Noble Sanctuary (Al-Aqsa Compound), similar to Judaism. That was a reason for Jews to mock Muslims and say that Muslims follow them; hence, they are superior. Prophet PBUH&HP waited 16 months for the divine revelation to let him change the Qiblah while he was disturbed by Jew's words. It was after such a long delay that he received a response: "turn your face towards the Holy Mosque, and wherever you may be, turn your faces towards it!" (2:144). If the Quran was Prophet Muhammad's PBUH&HP words, he could have changed the Qiblah much sooner and suffer less. 

4. Some Verses of the Quran Warn Prophet Muhammad PBUH&HP

In some of the verses of the Quran, Prophet Muhammad PBUH&HP is warned. In Surah Tawbah, he is told that: "May Allah excuse you! Why did you grant them to leave [to stay behind] before those who told the truth were evident to you, and you had ascertained the liars?" (9:43), or in another Ayat: "A prophet may not take captives until he has thoroughly decimated [the enemy] in the land." (8:67). Is it logical at all that someone blames himself and makes it public?

5. Prophet Muhammad PBUH & HP Was not Able to Read and Write

Prophet Muhammad PBUH&HP was not literate, and this is stated in the Quran and historical records. "You did not use to recite any scripture before it, nor did you write it with your right hand, for then the impugners would have been skeptical." (29:48). So, how can someone illiterate bring such eloquent words?

6. There is no Contradiction in the Quran

This holy book was revealed for 23 years. And something astonishing about the Quran is that there is no contradiction among the verses of it. If it was a human's words, there surely existed contradictions and errors in the Quran because human beings are forgetful, and for example, they forget what they told two years ago. But, this is not true about the Quran.

 References:

1. Allah's words
2. M. H. Hakimi, et al. "Al-Hayat," vol. 2, Translation: A. Aram, Iran, 1986.

    

Prophethood is a sublime status granted only to those who are chosen. A prophet deals with the heart and souls of humans; it is, therefore, a delicate matter to believe in the one who claims prophethood. Hence, there should be a sign that lets people recognize a real prophet from a fake one; that's "miracle." A "miracle" is an extraordinary act or event that no other human, from the first to the last, can perform it or cause it to happen, except a prophet. It can be neither explained by natural or scientific laws. For Prophet Muhammad (PBUH&HP), the Quran is known as an everlasting miracle that is the most outstanding of Prophet's (PBUH&HP) miracles. The question is: why the Quran is considered as a miracle? Let's find out the reasons.

1. The Quran Is Unique in Style and Inimitable

The Quran is revealed with great eloquence and fluency to convey the message. Precise, poetic, targeted, and meaningful terms used in the Quran are such that no weakness of expression can be found in any of its Ayats. In fact, the words are chosen such that they express the desired meaning in the best way possible (Fasaha) with the minimum usage of words (Balaqa). And, these are features that scholars of Arab literature have noticed in every chapter of the Quran [1]. 

What makes the Quran a miracle in this regard is that, until the present, no one has been able (and no one will be able) to bring even one short Surah similar to that of this holy book. A Surah that could express the highest scientific facts in simple, comprehensible words and describes different aspects of a scientific matter as clearly as possible. This is an issue that has already been addressed in the Quran: "And if you are in doubt concerning what We have sent down to Our servant, then bring a Surah like it, and invoke your helpers besides Allah, should you be truthful." (2:23). There is no historical account of those who succeeded in defeating this claim of the Quran. If there existed any, those who have always challenged the origin of the Quran should have recorded it. 

2. The Quran has been Brought by a Prophet Who Was Uninstructed (Ummi)

According to both historical records and the Quran, Prophet Muhammad (PBUH&HP) was Ummi before he was chosen as a messenger of Allah Almighty; he hadn't been taught by any teacher to read and write 1]. "You were not able to read or write before the Quran was revealed to you; however, the followers of falsehood would have tried to confuse the matter" (29:48). Therefore, the Quran that its words are in extreme eloquence and fluency and reveal sophisticated concepts cannot be Prophet's (PBUH&HP) word. Hence, it is a divine work gained through revelation, a "miracle." 

3. Scientific Facts Revealed by the Quran 

The Quran is not a book of science or a specialized book, nor has it aimed to concentrate on scientific facts. However, these kinds of information are stated in the Quran to demonstrate the wonders of creation and Allah Almighty's glory. 
In this regard, the creation of humans is described in detail in the Quran (23:12-14). In the first step, the human being was fashioned from clay. Other measures include the creation of man from spurting water, a drop of semen, the sperm fashioned into an embryo, this embryo fashioned into a shapeless lump of flesh. From the lump of flesh, fashioned bones, clothed the bones with flesh and then created the consanguinity and affinity [2].

The movement of the earth is another fact mentioned in the Quran: "It is Allah who raised the heavens without any pillars that you see" (13:2). In this verse, it is mentioned that there exist invisible supports that raise up the heavens. These supports are now referred to as the gravitational and other unseen forces in the universe. This scientific fact that is valid today was unknown in that era, and even one thousand years later when Galileo explained this fact and was sentenced to death. That's why it is not explicitly stated in the Quran; otherwise, it would have been banned [1].

4. Accurate Predictions 

Some accurate predictions are among the verses of the Quran. This proves that it has been descended from an absolutely knowing source that can report the unseen.

As an example, in the time of Prophet Muhammad (PBUH&HP), Mecca was controlled by polytheists for a while. They did not let Muslims enter the city and do the Hajj rituals. Then, Prophet (PBUH&HP) dreamed that he succeeded in performing Hajj with his companions. This was confirmed in an Ayah: "Certainly Allah has fulfilled His Apostle's vision in all truth: You will surely enter the Sacred Mosque, God willing, in safety, with your heads shaven or hair cropped, without any fear." (48:27). In the next year, this dream came true. 

In another case, the Quran has predicted that: "Byzantium has been vanquished in a nearby territory, but following their defeat, they will be victors in a few years." (30: 2-4). Some years later, both predictions came true. 

From what has been discussed above, it can be deduced that the Quran cannot be written by a human being. It is undoubtedly from a superior all-knowing all-wise source, which is Allah Almighty. Consequently, the Quran can be considered as one of Prophet Muhammad's (PBUH&HP) miracles, the greatest one, of course.

 References:

1. Quran
2. H. El-Ramady, et al., "Soils and Human Creation in the Holy Quran from the Point of View of Soil Science," Env. Biodiv. Soil Security, vol. 3, pp. 1- 9, (2019).