Thanks to its undisputed authenticity, the text of the Qur’an holds a unique place among the books of Revelation, shared neither by the Old nor the New Testament. In the first two sections of this work, a review was made of the alterations undergone by the Old Testament and the Gospels before they were handed down to us in the form we know today. The same is not true for the Qur’an for the simple reason that it was written down at the time of the prophet”.

One Article states:

On Quranic Structure..1. Each Qur’ânic sûrah has a dominant idea, called the axis of that sûrah, around which all the verses of that sûrah revolve. Thus no verse, or no group of verses, stands alone but has a direct relation with the axis of the sûrah and is part of the coherent scheme of the sûrah.2. The sûrahs of the Qur’ân exist in pairs, the two sûrahs of any pair being complementary to each other and, together constituting a unit. There are a few exceptions, however. The first sûrah, Fâtihah, does not have a complement, because it is a kind of a preface to the whole of the Qur’ân. All the other exceptions too are not exceptions in the real sense of the word since each one of them is an appendix to one or the other sûrah.

3. The 114 sûrahs of the Qur’ân fall into seven groups. The first group comes to an end at sûrah 5, the second at sûrah 9, the third at sûrah 24, the fourth at sûrah 33, the fifth at sûrah 49, the sixth at sûrah 66, and the seventh at sûrah 114. Each group contains one or more Makkan sûrahs followed by one or more Madînan sûrahs of the same cast. Like individual sûrahs or each pair of sûrahs, each group has a central theme which runs through all its sûrahs, knitting them into a distinct body. In each group, the themes of the other groups also occur but as subsidiary themes.

4. Each group logically leads to the next, and thus all the groups become variations on the basic theme of the Qur’ân, which is: ‘Allah’s call to man to adopt the right path’.

in Arabic that a person may refer to himself by the pronoun nahnu (we) for respect or glorification. He may also use the word ana (I), indicating one person, or the third person huwa (he). All three styles are used in the Qur’an, where Allaah addresses the Arabs in their own tongue.

Allaah, may He be glorified and exalted, sometimes refers to Himself in the singular, by name or by use of a pronoun, and sometimes by use of the plural, as in the phrase (interpretation of the meaning): ‘Verily, We have given you a manifest victory” [al-Fath 48:1], and other similar phrases. But Allaah never refers to Himself by use of the dual, because the plural refers to the respect that He deserves, and may refer to His names and attributes, whereas the dual refers to a specific number (and nothing else), and He is far above that.” (Al-‘Aqeedah al-Tadmuriyyah by Shaykh al-Islam Ibn Taymiyah, p. 75

Repetition:
The surah repeats a single account several times, like that of Musa (Moses) and Fir’awn (Pharaoh); Nuh (Noah); and Adam’s creation. This is done to connect and reconcile the subject with the details. This might also be to bring out the miraculous nature of the Qur’an and its eloquence. Knowledge of Arabic is required to fully appreciate this aspect of the Qur’an. All the stories come in a setting which differs from one place to another, according to the demands of the situation. This repetition has several important wisdoms:
a) To explain the importance and significance of the subject which the story deals with in order to firmly settle their lessons in the souls, e.g. the account of Moses and Pharaoh revolves around the clash between truth and falsehood, light and darkness, the allies of the most Merciful and the allies of the Devil.
b) To bring out and establish the miraculous nature of the Qur’an, as well as its peak of eloquence by bringing forth the same meaning in different ways and styles, such that the repetition does not seem repetitious! It requires a sound grasp of the Arabic language to fully understand this point. Consequently, all translations fail to convey the miraculous nature and the eloquence of the Qur’an.
c) The stories are narrated for a specific purpose. Some relevant details are mentioned at one place while some others are added or subtracted at other places. An example of this can be seen in the stories of the prophets in surah Hud which are repeated again in surah Al-Qamar, but with a new and different style and manner such that the reader might think that the stories and the events were not known to him before!

The Arabs Were  a highly Poetic People.they could go into a Desert and Recite 20 Verses.

Even Christian Arabs Cannot Deny the Poetic Masterpeice of the quran.

Now it is Unlikely a Persian who spoke Arabic for a Short time Could Produce the quran.