"Read in the Name of your Lord".  These were the first few words of the Qur'an revealed to the Prophet Muhammad over 1400 years ago. Muhammad, who was known to have been in retreat and meditation in a cave outside Mecca , had received the first few words of a book that would have a tremendous impact on the world of Arabic literature. Not being known to have composed any piece of poetry and not having any special rhetorical gifts,  Muhammed had just received the beginning of a book that would deal with matters of belief, legislation, international law, politics, ritual, spirituality, and economics  in an 'entirely new literary form'. Armstrong states,
"It is as though Muhammad had created an entirely new literary form…Without this experience of the Koran, it is extremely unlikely that Islam would have taken root." 
This unique literary form was the cause of the dramatic intellectual revival of desert Arabs , and after thirteen years of the first revelation, it became the only reference for a new state in Medina.  This new form of speech, the Qur'an, became the sole source of the new civilisation's political, philosophical, and spiritual outlook.
It is well known amongst Muslim and Non-Muslim scholars that the Qur’anic discourse cannot be described as any of the known forms of Arabic speech; namely Poetry and Prose. 
Taha Husayn,  a prominent Egyptian Litterateur, during the course of a public lecture summarised how the Qur’an achieves this unique form:
“But you know that the Qur’an is not prose and that it is not verse either. It is rather Qur’an, and it cannot be called by any other name but this. It is not verse, and that is clear; for it does not bind itself to the bonds of verse. And it is not prose, for it is bound by bonds peculiar to itself, not found elsewhere; some of the binds are related to the endings of its verses and some to that musical sound which is all its own. It is therefore neither verse nor prose, but it is “a Book whose verses have been perfected the expounded, from One Who is Wise, All-Aware.” We cannot therefore say its prose, and its text itself is not verse. It has been one of a kind, and nothing like it has ever preceded or followed it.” 
Any expression of the Arabic language falls into the literary forms of Prose and Poetry. There are other ‘sub’ forms that fall into the above categories. Kahin, which is a form of rhymed prose, is one of these ‘sub’ forms; but all literary forms can be described as prose and poetry.
Arabic Poetry is a form of metrical speech with a rhyme.  The rhyme in Arabic poetry is achieved by every line of the poem ending upon a specific letter.  The metrical aspect of Arabic poetry is due to its rhythmical divisions, these divisions are called ‘al-Bihar’, literally meaning ‘The Seas’ in Arabic. This term has been used to describe the rhythmical divisions as a result of the way the poem moves according to its rhythm.
In Arabic poetry there are sixteen rhythmical patterns, which all of Arabic poetry adheres too or is loosely based upon;
Each one of the al-Bihar have a unique rhythmical division.  The al-Bihar were first codified in the 8th century by al-Khalil bin Ahmad and have changed little since. The al-Bihar are based on the length of syllables. A short syllable is a consonant followed by a short vowel. A long syllable is a vowelled letter followed by either an unvowelled consonant or a long vowel. A nunation sign at the end of a word also makes the final syllable long. In Arabic poetry each line is divided into two halves.
Below are basic scansions of the metres commonly found in Arabic poetry, showing long (—) and short (^) syllables. They represent pairs of half-lines and should be read from left to right. The patterns are not rigidly followed: two short syllables may be substituted for a long one.
An example of an Arabic poem, is the ancient Arabian poem called ‘Abu-l-‘Ata of Sind’:
Of thee did I dream, while spears between us were quivering And sooth, of our blood full drop had drunken the tawny shafts! I know not, by heaven I swear, and true is the word I say This pang, is it love sickness, or wrought by a spell from thee. If it be a spell, then grant me grace of my love-longing If other the sickness be, then none is the guilt of thine. 
This poem, in the original Arabic, falls into the rhythmical pattern of Tawil, one of the al-Bihar shown above.  A literary analysis on any Arabic Poem will conclude that it adheres too or is based upon the rhythmical patterns. This is supported by Louis Cheikho who collected pre-Islamic and Islamic poetry and concluded that all of the poems conformed and were based upon the al-Bihar. 
Arabic Prose can be called non-metrical speech, meaning it does not have a rhythmical pattern like poetry mentioned above. Arabic prose can be further divided into two categories; Saj’ which is rhymed prose and Mursal which is straight prose or what some may call ‘normal speech’. 
An apt description of Saj’ is, in the words of Von Deffer:
“A literary form with some emphasis on rhythm and rhyme, but distinct from poetry. Saj’ is not really as sophisticated as poetry, but has been employed by Arab poets, and is the best known of the pre- Islamic Arab prosodies. It is distinct from poetry in its lack of metre, i.e. it has not consistent rhythmical pattern, and it shares with poetry the element of rhyme, though in many cases some what irregularly employed.” 
Mursal can be defined as a literary form that goes on and is not divided, but is continued straight throughout without any divisions, either of rhyme or of anything else.  Mursal is meant as a way of expression close to the everyday spoken language, examples can be seen in speeches and prayers intended to encourage or motivate the masses.
The Qur’ans Literary Form
The Qur’anic discourse cannot be described as any of the known literary forms. The most predominant opinion is that it doesn’t adhere to any of the rules known to poetry and prose. Another opinion is that the Qur’an combines metrical and non-metrical composition to create its own literary form. Some scholars disagree with the above opinions and claim that the Qur’an is a form of rhymed prose, saj’. This opinion has arisen mainly due to the similarities of pre-Islamic prose and early Meccan chapters of the Qur’an. However, the scholars who carry this opinion do not contend that the Qur’an is unique by its use of literary and stylistic elements that render it inimitable. This unique use of literary elements has not been found in any Arabic Prose, past or present.
Below is an explanation, with reference to the main opinions above, on how the Qur’an achieves its unique inimitable form.
Non-compliance to the Rules of Prose or Poetry
The Qur’anic literary form differs as it does not fit in to any of the literary categories explained above,  it is not like the prose of Saj’ or Mursal and it doesn't fit into any of the al-Bihar. This can be seen by the following example:
Wad Duha wal laili idha saja Ma waddaka Rabbuka wa maa qala Wa lal akhiraatu khairul laka minal oola Wa la sawfa ya teeka Rabbuka fa tarda… By the morning hours and by the night most still Your Lord has neither forsaken you nor hates you And indeed the hereafter is better for you than the present And verily your Lord will give you so that you shall be well pleased… 
The examination of the whole chapter with reference to the above literary forms indicates that it is not Saj’ or Mursal as this verse has an internal rhythm, whereas Saj’ does not have a consistent rhythm and Mursal has no rhythm or rhyme. Also it cannot be described as poetry; the totality of this chapter, or any other chapter for that matter, does not adhere to any of the al-Bihar.
Unique Fusion of Metrical and non-Metrical Speech
Some parts of the Qur’an follow the rules of poetry, that is, some verses can be described as one of the al-Bihar.  When the totality of a Qur’anic Chapter, that contains some these verses is analysed, it is not possible to distinguish its literary form.
“The Qur'an is not verse, but it is rhythmic. The rhythm of some verses resemble the regularity of saj’ …But it was recognized by Quraysh critics to belong to neither one nor the other category.” 
The Qur’an achieves this unique literary form by intermingling metrical and non-Metrical speech in such a way that the difference can not be perceived.  This intermingling of metrical and non- metrical composition is present throughout the whole of the Qur’an. The following examples illustrate this,
“But the righteous will be in Gardens with Springs – ‘Enter in Peace and Safety!’ – and We shall remove any bitterness from their hearts: [they will be like] brothers, sitting on couches, face to face. No weariness will ever touch them there, nor will they ever be expelled. [Prophet] tell My servants that I am the Forgiving, the Merciful, but My torment is the truly painful one. Tell them too about Abraham’s guests: when they came to him and said “Peace,” he said, ‘We are afraid of you’” 
When reading the original Arabic of the above verse the reader moves from metric composition to prose with out experiencing the slightest change of style or mode.  The same mingling of metrical and non-metrical composition can be observed in the following verse from Chapter 12 of the Qur’an.
“When she heard their malicious talk, she prepared a banquet and sent for them, giving each of them a knife. She said Joseph, ‘Come out and show yourself to them!’ and when the women saw him, they were stunned by his beauty, and cut their hands, exclaiming, ‘Great God! He cannot be mortal! He must be a precious angel!’ She said, ‘This is the one you blamed me for. I tried to seduce him and he wanted to remain chaste, but if he does not do what I command now, he will be put in prison and degraded.’” 
The phrase “This is the one you blamed me for” in Arabic is poetic. It has a metrical structure in which the rules of Arabic poetry are observed,  Commenting on this feature Mitwalli states,
“It is almost impossible for the listener to detect the shift from one form to the other, nor does this exquisite mingling impinge on the fluidity of expression or impair its meaning.” 
The Qur’an is truly unique in composition. It is neither prose nor poetry.  This inimitable style is achieved by intermingling metrical and non-metrical composition and by not adhering to the rules of poetry or prose. In addition to this, the Qur’an uses expressions that are eloquent, full of sublime rhetoric and adheres to the grammatical rules of Classical Arabic. 
Literary and Stylistic Differences
The most predominant opinion on the inimitability of the Qur’an is that it exhibits a unique literary form. However, some Scholars are of the opinion that the early Meccan chapters have similar structural features than that of the kahin form of rhymed prose . These same Scholars still admit that the Qur’ an is unique due to its stylistic and literary features . This could be the main reason why those who used to recite in the kahin form of Arabic were not able to challenge the Qur’an. But this can also raise the question ‘If the Qur'an is a form of rhymed prose then why were those who used kahin unable to challenge the Qur'an?’ 
Even if this opinion is accepted, the stylistic and literary features that render the Qur’an inimitable and unique include semantically driven assonance and rhyme , grammatical shift ; interrelation between sound, structure and meaning  and its unique linguistic genre.  These are valid and powerful arguments that explain how the Qur'an differs from rhymed prose from a literary and stylistics point of view. Please see references above for more information.
A note on Western Scholarship
Non-Muslim Scholarship testifies that the Qur’an has a unique literary form. Some of these western Scholars include Robinson, Gibb, Arberry, Zammit, Lawrence, Johns, Casanova, Nicholson, Kasis and many others.  For example Arberry states.
“For the Koran is neither prose nor poetry, but a unique fusion of both” 
What must be noted is that some of the Western Scholars who continue to call the Qur’an’s literary form as rhymed prose do so on the basis that the Qur’ans uniqueness is acknowledged. To illustrate this R. A. Nicholson in his book ‘Literary History of the Arabs’ states,
“Thus, as regards its external features, the style of the Koran is modelled upon saj’, or rhymed prose, of the pagan soothsayers, but with such freedom that it may fairly be described as original.” 
Although they try to fit the Qur’an into rhymed prose they still concluded that it is a unique or an original form of rhymed prose, thus supporting our hypothesis. To highlight this fact Bruce Lawrence states,
“Those passages from the Qur’an that approach saj’ still elude all procrustean efforts to reduce them to an alternative form of saj’.” 
This analysis has been summarised by Ibn Khaldun’s in his classical work ‘The Muqadimah’:
“It should be known that the Arabic language and Arab speech are divided into two branches. One of them is rhymed poetry…The other is prose, that is, non-metrical speech…The Quran is in prose. However, it does not belong in either of the two categories. It can neither be called straight prose nor rhymed prose. It is divided into verses. One reaches breaks where taste tells one that speech stops. It is then reused and ‘repeated in the next verse. (Rhyme) letters, which would make that (type of speech) rhymed prose are not obligatory, nor do rhymes (as used in poetry) occur.” 
A note on ‘Subjective and Aesthetic Criteria’
Some Qur’an critics often claim that the Qur’anic challenge is subjective and is based upon aesthetic criteria. This is a false accusation. The Qur’an can either be described as prose, poetry or unique. Literary forms are not based upon aesthetic criteria; they are based upon the structural features of a text. It can be clearly seen above that literary forms are defined and can been distinguished from one another.
The Qur’an is a unique form of Arabic speech. The form of its language can not be described as Prose or Poetry. It achieves this unique literary form by intermingling metrical and non-metrical speech in such a way that its style is not affected and its meaning not distorted. Furthermore, the Qur’an does not adhere to the rules of Prose or Poetry but yet its expression is grammatically sound. This can been seen by analysing every Qur’anic chapter. The totality of every chapter has a special character, with its own unique form, and its unique use of literary devices. These features of the Qur'an are part of the reason of why it has not been emulated to this day.  Hammilton Gibb’s states,
“.…the Meccans still demanded of him a miracle, and with remarkable boldness and self confidence Muhammad appealed as a supreme confirmation of his mission to the Koran itself. Like all Arabs they were connoisseurs of language and rhetoric. Well, then if the Koran were his own composition other men could rival it. Let them produce ten verses like it. If they could not (and it is obvious that they could not), then let them accept the Koran as an outstanding evidential miracle” 
There are many Muslim and Non-Muslim Scholars who testify that the Qur’an is indeed unique and inimitable. An interesting analysis by Aisha Abd al-Rahman, which built upon the works of many Islamic Scholars throughout the decades, supports the conclusion voiced by Taha Hussein that ‘Arabic composition should be divided into three categories, prose, verse and Qur’an, saj’ forming a part of prose but the Qur’an being a category of its own.’ 
As a result of researching Western and Muslim Scholarship it can concluded that the Qur’an is a unique literary form that cannot be emulated. Further research into the references below will consolidate the points raised in this article and will provide the correct understanding on how no one has been able to produce anything like the Qur’anic discourse. To conclude, E. H. Palmer correctly asserts,
“That the best of Arab writers has never succeeded in producing anything equal in merit to the Qur'an itself is not surprising.” 
 Qur’an Chapter 96 Verse 1. This verse is known to have been the first revelation, there is a consensus amongst the scholars on this issue. Please see http://www.usc. edu/dept/MSA/quran/maududi/mau96.html for further information.
 Please see Martin Lings. Muhammad: His Life Based on the Earliest Sources. 1987. Inner Traditions; for a detailed account on the life of the Prophet Muhammad and details of the first revelation.
 The Qur’an is undoubtedly the most influential book in Arabic literature. Non-Muslim and Muslim Scholars do not contend that the Qur’an is an authority in Arabic literature and has had an unparalleled influence. For example Chicago University Wadad Kadi and Mustansir Mir, Professor of Islamic studies at Youngstown State University state that:
"Although Arabic, as a language and a literary tradition, was quite well developed by the time of Muhammad's prophetic activity, it was only after the emergence of Islam, with its founding scripture in Arabic, that the language reached its utmost capacity of expression, and the literature its highest point of complexity and sophistication. Indeed, it probably is no exaggeration to say that the Qur'an was one of the most conspicuous forces in the making of classical and post-classical Arabic literature." Wadad Kadi and Mustansir Mir, Literature and the Qur'an, Encyclopedia of the Qur'an, vol. 3, pp. 213, 216
Please also see Muhammed Abdel Haleem. 1999. Understanding the Qur’an: Themes & Styles. I. B. Tauris Publishers, p. 1 - 4
 Understanding the Qur’an: Themes & Styles, p. 1
 The Qur’an is a book that gives guidance on all of life’s affairs. This includes the personal and political sphere, for example the Qur’an details how treaties with other nations should be undertaken and how prisoners of war should be treated (Understanding the Qur’an: Themes & Styles, p. 66-67)
 K. Armstrong. 1993. A History of God: the 4,000 Year Quest of Judaism, Christianity and Islam. Vintage, p. 171
 Part of the Qur’an’s intellectual miracle is its literary form. God has challenged the whole of mankind to try and produce a single chapter like it (Qur’an 2:23). This challenge, which has remained unchallenged, is what captivated the minds of the Arabs at the time of revelation. They rationally assessed that if an Arab cannot challenge the Qur’an and a Non-Arab could not, then the only ‘entity’ that could have possibly produced the Qur’an is the Creator. Margoliouth explains the results of this intellectual revival,
"The Koran [sic] admittedly occupies an important position among the great religious books of the world. Though the youngest of the epoch-making works belonging to this class of literature, it yields to hardly any in the wonderful effect which it has produced on large masses of men. It has created an all but new phase of human thought and a fresh type of character. It first transformed a number of heterogeneous desert tribes of the Arabian peninsula into a nation of heroes, and then proceeded to create the vast politico-religious organizations of the Muhammadan world which are one of the great forces with which Europe and the East have to reckon today." G. Margoliouth. 1977. Introduction to J.M. Rodwell’s, The Koran. Everyman’s Library, p. vii
 To understand the functions and objectives of this state, and its impact on the modern world please see the very informative site www.caliphate.eu
 Please see F Esack. 1993. Qur’anic Hermeneutics: Problems and Prospects. The Muslim World, Vol. 83, No. 2. p. 126 -128; H E Kassis. 1983. A Concordance of the Qur’an. University of California Press, p. xvii; Arthur J Arberry. 1998. The Koran. Oxford University Press, p. x and Bruce Lawrence. Journal of Qur’anic Studies. Vol VII, Issue I 2005. Approximating Saj’ in English Renditions of the Qur’ an: A Close Reading of Suran 93 (al-Duha) and the basmala p. 64
 The influential Egyptian Litterateur born in 1889 and died in 1973.
 Lecture entitled "Prose in the second and third centuries after the Hijra" delivered at the Geographical Society in Cairo 1930. Dar al Ma-arif.
 Metrical speech is a form of speech that employs a strict rhythmical pattern, that is, it follows a type of poetic metre.
 Sir Charles J. Lyall. 1930. Translations of Ancient Arabian Poetry. Columbia University Press, p. xlv
 Please see Sir Charles J. Lyall. Translations of Ancient Arabian Poetry, p. xlv-lii and William Wright. 1955 (1898). A Grammar of the Arabic Langugage, Vol II, part 4. Cambridge University Press, p. 350- 390 for more information on the poetic metres.
 Sir Charles J. Lyall. Translations of Ancient Arabian Poetry, p 13.
 Louis Cheikho, Shu’ara' 'al-Nasraniyah, 1890-1891, Beirut.
 A. Von Deffer. 2003 (Revised Ed. 1994). ‘Ulum al-Qur’an: An Introduction to the Sciences of the Qur’ an. The Islamic Foundation, p. 75
 See reference 
 Qur’an Chapter 93 Verses 1-4
 Kristina Nelson. 1985 (2nd Print 2002). The Art of Reciting the Qur’an. The American University in Cairo Press, p. 10
“Although some of the lines of the Qur’an may be scanned according to the Classical Arabic metres*, these are not as characteristic of Qur’anic syllabic rhythmic patterns as are the abrupt or progressive shifts in rhythmic patterns and length of line, and the shifts between regular and irregular patterns.” * See al-Sa’id (1997: 324 – 25) and al-Suyuti (1910: I/96 – 105) for a list of some of these lines.
 A F L Beeston, T M Johnstone, R B Serjeant and G R Smith (Editors), Arabic Literature To The End Of The Ummayad Period, 1983, Cambridge University Press, p. 34.
 Mitwalli al-Sharawi, The Miracles of the Qur’an. Dar ul Taqwa, p. 31
 Qur'an Chapter 15 Verses 45-52
 The Miracles of the Qur’an, p. 31
 Qur’an Chapter 12 Verses 31-35
 The Miracles of the Qur’an, p. 31-32
 Ibid, p. 32
 See reference  and Mitwalli al-Sharawi, The Miracles of the Qur’an.
 For more information on the Rhetorical Features in the Qur’anic discourse see H Abdul-Raof. 2003. Exploring the Qur’an, p. 265-398 and F Esack. 1993. Qur’anic Hermeneutics: Problems and Prospects. The Muslim World, Vol. 83, No. 2. p. 126 -128.
 Please see www.theinimitablequran.com/InterrelationOfStructureSoundMeaningSurah103And104. html, Sayyid Qutb. 1966. al-Taswir al-Fanni fi al-Qur’an. Cairo: Dar al-Ma’arif, Sayyid Qutb. 1966. Mashahid al-Qiyama fi ‘l-Qur’an. Cairo: Dar al-Ma’arif., Michael Sells. 1991. Sound Spirit and Gender in Surat al-Qadr. Journal of the American Oriental Society 111, 2 p. 239-259, M. Sells. Sound and Meaning in Surat Al- Qariah in Arabica Vol 40, and M. Sells. 2000. A Literary Approach to the Hymnic Surahs of the Qur'an: Spirit, Gender and Aural Intertextuality. Curzon Press, p. 3-25.
 Please see www.theinimitablequran.com/UniqueGenre.html for more details.