Contrary to the repeated assertion of Muslims, the Quran does not proclaim an absolute pure form of monotheism (tauhid) since it does not depict Allah as a singular monad.
Take, for instance, what the following verses teach in respect to the revelation and collection of the Islamic text:
Stir not thy tongue herewith to hasten it. Lo! upon US (resteth) the putting together thereof and the reading thereof. And when WE read it, follow thou the reading; Then lo! upon US (resteth) the explanation thereof. S. 75:16-19 Pickthall
And they say: O thou unto whom the Reminder is revealed, lo! thou art indeed a madman! Why bringest thou not angels unto us, if thou art of the truthful? WE send not down THE ANGELS save with the Fact, and in that case (the disbelievers) would not be tolerated. Lo! WE, even WE, reveal the Reminder, and lo! WE verily are its Guardian. WE verily sent (messengers) before thee among the factions of the men of old. S. 15:6-10 Y. Ali
Pay careful attention how the foregoing passage distinguishes the plural referent from the angels, showing that angelic creatures are not included with those who sent down the Quran, nor are they the ones that preserve it.
This confirms that it is Allah alone that is speaking in the plural, e.g., Allah is they who sent down the Quran, and Allah is the ones who read it to Muhammad and they will be the ones to collect it together.
And yet, interestingly, we are told elsewhere that it was the Holy Spirit and Gabriel that brought down the Quran to Muhammad:
Say: Whoever is an enemy to Gabriel – for he brings down the (revelation) to thy heart by God’s will, a confirmation of what went before, and guidance and glad tidings for those who believe, – S. 2:97 Y. Ali
Say, the Holy Spirit has brought the revelation from thy Lord in Truth, in order to strengthen those who believe, and as a Guide and Glad Tidings to Muslims. S. 16:102 Y. Ali
The ahadith take it a step further and claim that Q. 75:18, which plainly states that it is Allah who reads/recites the Muslim scripture to Muhammad,
Thus, when WE recite it, follow thou its wording [with all thy mind]: Muhammad Asad
Actually refers to (or at the very least includes) Gabriel since he was the one that taught Muhammad how to recite the Quran!
5. Sa’id ibn Jubayr related that Ibn ‘Abbas said about the words of Allah the Almighty, “Do not move your tongue trying to hasten it” (75:16): “The Messenger of Allah used to experience hardship while receiving the revelation and he used to move his lips [for committing it into memory instantly].” Ibn ‘Abbas said, “I am moving my lips for you as the Messenger of Allah moved his.” Sa’id ibn Jubayr said, “I am moving my lips as I saw Ibn ‘Abbas moving his,” and he moved his lips.
“So Allah the Almighty sent down, ‘Do not move your tongue trying to hasten it. Its collection and recitation are Our responsibility.’ He said that ‘collecting it’ means ‘in your heart’ and your reciting it [it as it was revealed]’. ‘So when We recite it, follow its recitation,’ means ‘listen and be silent’. ‘Then its explanation is also Our responsibility‘ means that it is up to Us [to do that] when you recite it. After that, the Messenger of Allah would listen when Jibril came to him. When Jibril left, then the Prophet would recite it AS JIBRIL RECITED IT.” Aisha Bewley, The Sahih Collection of Al-Bukhari, Chapter 1: The Beginning of the Revelation http://bewley.virtualave.net/bukhari1.html#1; capital emphasis mine)
XLIII. The words of Allah Almighty, “Do not move your tongue trying to hasten it. “ (75:16) and what the Prophet did when the revelation was sent down on him
Abu Hurayra said that the Prophet said, “Allah Almighty said, ‘I am with My slave whenever he remembers Me and whenever his lips move with My remembrance.”
7086. Sa’id ibn Jubayr related from Ibn ‘Abbas about His words, “Do not move your tongue trying to hasten it” (75:16), “The Messenger of Allah used to experience hardship while receiving the revelation and he used to move his lips [for committing it into memory instantly].” Ibn ‘Abbas said to me, “I am moving my lips for you as the Messenger of Allah moved his.” Sa’id said, “I am moving my lips as I saw Ibn ‘Abbas moving his,” and he moved his lips. So Allah the Almighty sent down, ‘Do not move your tongue trying to hasten it. Its collection and recitation are Our affair.’ He said that ‘its collection’ is in your heart and then your reciting it [as it was revealed]. ‘So when We recite it, follow its recitation’ means: ‘listen to it and be silent. Then it is up to Us to make you recite it.’ After that, the Messenger of Allah would listen when Jibril came to him. When Jibril left, then the Prophet would recite it AS JIBRIL HAD RECITED IT.” (Bewley, Al-Bukhari, 100. Book of Tawhid (the belief that Allah is One in His Essence, Attributes and Actions) http://bewley.virtualave.net/bukhari52.html#tawhid; capital emphasis mine)
How the Prophet received the Revelation
This is Allah teaching His Messenger how to receive the revelation from the angel. For verily, he (the Prophet) was rushing in his attempts to grasp the revelation and he would be reciting the revelation with the angel while he was reciting it. Therefore, Allah commanded him that when the angel brings some revelation to him he should just listen. Allah would make sure to collect it in his chest, and He would make it easy for him to recite it in the same way that it was revealed to him. Allah would explain it, interpret it and clarify it for him. So the first phase was gathering it in his chest, the second phase was recitation and the third phase was its explanation and clarification of its meaning. Thus, Allah says,
(Move not your tongue concerning to make haste therewith.) meaning, with the Qur’an. This is as Allah says,
(And be not in haste with the Qur’an before its revelation is completed to you, and say: “My Lord! Increase me in knowledge.”) (20:114) Then Allah says,
(It is for Us to collect it) meaning, `in your chest.’
(and that it be recited.) meaning, `that you recite it.’
(And when We have recited it to you,) meaning, `when the angel has recited it to you from Allah,’
(then follow its recitation.) meaning, `listen to it then recite it as he taught you to recite it.’
(Then it is for Us to make it clear.) meaning, `after memorizing it and reciting it, We will explain it to you, clarify it and inspire you with its meaning according to what We intended and legislated.’ Imam Ahmad recorded from Ibn `Abbas that he said that the Messenger of Allah used to struggle very hard to grasp the revelation and he used to move his lips (rapidly with the recitation). The narrator, Sa`id, then said, “Ibn `Abbas said to me, `I will move my lips like the Messenger of Allah used to move his lips (in order to show you).’” Then, the subnarrator said, “And Sa`id said to me, `I will move my lips like I saw Ibn `Abbas moving his lips (in order to show you).’” Then Allah revealed,
(Move not your tongue concerning to make haste therewith. It is for Us to collect it and that it be recited.) Ibn `Abbas said, “This means He will collect it in his chest to recite it.
(And when We have recited it to you, then follow its recitation.) meaning, listen to it and pay attention.
(Then it is for Us to make it clear (to you).) So after this, when Jibril would leave, he would recite it AS JIBRIL HAD TAUGHT HIM TO RECITE IT.” This has also been recorded by Al-Bukhari and Muslim. Al-Bukhari’s wording says, “So whenever Jibril would come to him he would be silent, and when Jibril had left he would recite it just as Allah, the Mighty and Sublime had promised him.” (Tafsir Ibn Kathir, http://www.alim.org/library/quran/AlQuran-tafsir/TIK/75/16; capital emphasis mine)
What this shows is that Allah, the Holy Spirit and Gabriel all make up the identity of the plural referent of Q. 15:6-10 and 75:16-19. I.e., Allah, the Spirit and Gabriel make up the the plural We/Us that taught and collected the Muslim scripture. This in turn means that the Allah of the Quran isn’t a singular monad but a plural entity whose identity includes both the Holy Spirit and Gabriel.
So much for the Islamic scripture being perfectly clear and eloquent, or for the Islamic faith being the purest form of unitarian monotheism.