muhammad asad wrote that all religions, not only islam, rely on the fact that “only a small segment of reality is open to man's perception and imagination, and that by far the larger part of it escapes his comprehension altogether.” equally important is the idea that the human mind “can operate only on the basis of perceptions previously experienced by that very mind either in their entirety or in some of their constituent elements…” in other words, we cannot form a clear idea of something that happens entirely outside the realm of our past experiences; and that being so, it is natural that we find it difficult to comprehend the full meaning and relevance of mystical experiences like revelation.
indeed, the qur’an makes a clear distinction between the perceptible world of experience (shahadah) and the unseen world of transcendental reality (ghayb). revelation (wahy) is a means for god’s specially chosen messengers to receive divine messages; we may call it an exclusive channel of communication accessible to the prophets. for this reason, by way of objective investigation, we can only study the credibility of the person who claims to have received the wahy, learn the circumstances, and observe the results. from these, we can arrive at some conclusions. the qur’an says what means:
*{it is not fitting for a man that god should speak to him except by inspiration, or from behind a veil, or by sending of a messenger to reveal with god’s permission what god wills: for he is most high, most wise.}* (ash-shura 42:51)
this means that god does not hold a face-to-face talk with any human. the divine message comes to the prophets through the angel gabriel. there are other exceptional cases like abraham (peace be upon him) getting god’s message in a dream or moses (peace be upon him) hearing god speaking to him from behind a burning bush. but again, these are exceptional cases.
here is an account of the prophet muhammad (peace be upon him) receiving the first revelation. according to `a’ishah (may allah be pleased with her), the prophet used to go in seclusion in the cave of hiraa’, where he used to worship allah alone continuously for many days before he desired to see his family. he used to take with him food for the stay and then come back to his wife khadijah to take his food again, till suddenly the truth descended upon him while he was in the cave of hiraa’.
the angel came to him and asked him to read. the prophet replied, “i do not know how to read.” the prophet added in his report: the angel caught me [forcibly] and pressed me so hard that i could not bear it any more. he then released me and again asked me to read and i replied, “i do not know how to read.” thereupon he caught me again and pressed me a second time till i could not bear it any more. he then released me and again asked me to read, but again i replied, “i do not know how to read (or what shall i read?).” thereupon he caught me for the third time and pressed me, and then released me and said: *{read, in the name of your lord, who created, created man from a clot. read! and your lord is the most bountiful}* (al-bukhari and muslim).
this happened in the year 610 ce, when the prophet was forty years old. about the nature of the revelation, the prophet is reported to have said: “sometimes it is ‘revealed’ like the ringing of a bell, this form of inspiration is the hardest of all and then this state passes off after i have grasped what is inspired. sometimes the angel comes in the form of a man and talks to me and i grasp whatever he says” (al-bukhari).
during the twenty-three years from the revelation of the first verses (recorded in surat al-`alaq 96:1-5), the qur’an was revealed to the prophet in stages. there are a number of reasons why the qur’an was not revealed at one time. the most important objectives of this were to enable the natural and steady development of the community of believers by gradually implementing the laws of god; to meet the requirements of the changing conditions and needs of that community; and to facilitate easy absorption and memorization of the qur’an.
it is noteworthy that when the revelation progressed, the prophet encouraged his companions to learn as many verses as possible. and what is more, whenever a revelation came, he called for a scribe and dictated it to him. he was careful to keep the revealed verses safely recorded. consequently, the qur’an was available in written form during the prophet’s own time. it is clear from this verse, which says what means:
*{... this is indeed a qur'an most honorable, in a book (kitab) well guarded, which none shall touch but those who are clean: a revelation from the lord of the worlds.}* (al-waqi`ah 56:77-80)
also it is quite evident from the prophet’s last sermon that the qur’an in the written form—though not necessarily in a single volume—existed during his time. he said: “i have left with you something which if you will hold fast to, you will never fall into error—a plain indication, the book of god and the practice of his prophet” (ibn hisham).
there are also three hadiths in sahih al-bukhari that inform us that the angel gabriel used to recite the qur’an with the prophet once a year, but gabriel recited it twice with him in the year he died.
from the foregoing account of the process of revelation and the recording and collection of the qur’an, it must be evident that there was no chance for any of god’s words in the qur’an to be distorted. but you have also asked, “how much influence did the prophet muhammad (peace be upon him) have on the revealed words in the qur’an?”
by “the influence of the prophet” on the revealed words in the qur’an, are you suggesting that the prophet himself could be guilty of misrepresenting or misinterpreting the words of god? if so, the answer is no, the prophet could not have done this because, allah himself chose him as his prophet and allah will not allow any one, even his prophet, to scuttle his purpose or undermine his message. as for others, they are free to accept allah’s guidance or reject it, as it is clearly mentioned in the qur’an itself. the qur’an says what means:
*{say, “the truth is from your lord”: let him who will, believe, and let him who will, reject [it] …” }* (al-kahf 18:29)
your question can also suggest another possibility: that the words of the qur’an are not necessarily allah’s, but those of the prophet. this possibility also is ruled out by the qur’an and the authentic records of the prophet’s life. whatever revelation the prophet heard was immediately dictated to his companions for writing down then and there. and there was no question of the prophet putting the ideas in his own words.
there are clear accounts by the poets of the prophet’s time, that the language of the qur’an is so superb that none of them could excel it or match it. and all of them knew muhammad (peace be upon him) and they were sure that he could never have composed the verses of the qur’an. this was the reason why many of them embraced islam. allah asks in the qur’an what means:
*{do they say: “he forged it”? say: “bring then a chapter like it and call [for help] anyone you can, other than god, if you are honest}* (yunus 10:38).
and again, the qur’an says what means:
*{what! do they say, “he has forged a falsehood against god”? but if god willed, he could seal up thy heart. and god blots out vanity, and proves the truth by his words. for he knows well the secrets of all hearts}* (ash-shura 42:24).
it is quite evident that there was no chance at all for the prophet to distort or change the words of the message he got from allah. and moreover, the honesty and trustworthiness of the prophet was never questioned by any one who knew him, not even by his staunchest enemies. indeed he was called “al-amin” (the trustworthy).
allah almighty says what means:
*{the truth is from your god alone; so be not of those who doubt}* (aal `imran 3:60).