A Journal of Islamic Studies
If the Qur'an had contained anything other than Arabic, then it would be thought that Arabic was incapable of expressing those things in its own words. 
Later scholars, however, viewed lexical borrowing differently. Thus, al-Suyuti explained that the adoption of some non-Arabic words in the Qur'an took place because such words denoted objects or ideas for which no Arabic words were readily available.  Examples include the Persian words 'istibraq' (a thick, silky brocade), 'ibriq' (a water jug); the Nabatean word 'akwab' (goblets); the Aramaic word 'asfar' (a large book); the Hebrew borrowing 'rahman' (merciful); and the Syriac words 'zayt' (olive oil) and 'zaytun' (the olive tree). The Qur'an has several hundred such foreign borrowings. Earlier generations of Muslim scholars maintained that such words were either ancient Arabic words that had gone out of use until the revelation of the Qur'an, or that such words were ancient borrowings introduced into Arabic long before the Revelation which had since then acquired an Arabic pattern. 
Whether we agree with the view that foreign words in the Qur'an are direct borrowings from other languages or with the view that the majority of these words were ancient borrowings which occurred in pre-Islamic poetry and which had been in use long before the revelation of the Qur'an, it is a fact that the Qur'an contains words that are not of Arabic origin. Such words come from a host of languages including Ethiopic, Persian, Greek, Sanskrit, Syriac, Hebrew, Nabatean, Coptic, Turkish, and Berber.  By adopting words of non-Arabic origin, the Qur'an may have helped to legitimize a very important linguistic process, that of lexical borrowing. The importance of this practice derives particularly from the fact that the use of foreign words was viewed unfavourably by a large number of Arab scholars at that time.  The term 'ajami (Persian, foreign) was used strictly in reference to non-Arabic words to set them aside from native Arabic words. During the documentation of the grammar in the first three centuries of the Islamic calendar, the same term was used to refer to less-than-native pronunciations of Arabic. In their attempt to document the grammar, the early scholars considered the speech of the bedouins in the heart of the desert to be the most reliable and purest, apparently due to their belief that the bedouins seldom left the desert or mixed with speakers of other languages.  Likewise, the early grammarians did not look favourably upon the adoption of foreign terms into Arabic, apparently in the belief that borrowing would indicate certain gaps or deficiencies in the language.
Since it contained words of non-Arabic origin, the Qur'an established a precedent for lexical borrowing as a tool whereby languages may enrich themselves. This was clearly one of the most innovative aspects of the Qur'an. It is particularly important given the unfavourable climate that prevailed among the early Muslim scholars with respect to lexical borrowing.
Structure and style
The Qur'an has made remarkable contributions to the structure and style of the Arabic language. It combines within its covers the first documentation of the sentence patterns of Arabic, and it was instrumental in the documentation of Arabic grammar which began in the first Islamic century. From the time of Sibawayh (d. c. 793) up to the present day there is hardly a page in any manual of Arabic grammar which does not contain one or more verses from the Qur'an. Furthermore, the strong interest in Qur'anic studies brought with it an equally strong interest in Arabic linguistic studies.
The style of the Qur'an helped to develop and enrich the Arabic language. As the first book in the Arabic language, it introduced stylistic innovations which greatly influenced trends in subsequent generations. Foremost among such trends is the Qur'an's abundant use of figures of speech in place of simple words. The Qur'an makes extensive use of illustrations, imagery, and metaphor, thus adding beauty, life, and colour to plain words In fact, the ubiquity of figures of speech in the Qur'an has led Sayyid Qutb to conclude that 'the use of imagery and figures of speech is the Qur'an's preferred style.'  The preference for figures of speech over plain words appears to be a general trend that permeates the entire Book. Thus, the Qur'an affirms the impossibility of the disbelievers' entry into paradise:
Nor will they enter the Garden until a thick rope can pass through the eye of a needle. (7: 40)
Confirming that the disbelievers' actions will be in vain, the Qur'an conveys this notion in the following way:
The parable of those who reject their Lord is that their works are as ashes on which the wind blows furiously as on a tempestuous day. (14: 18)