Belief of the Salaf Concerning the Quran
Question

We would like to know what the Salaf (righteous predecessors) believed concerning the Noble Quran.
Praise be to Allah.Shaykh Ibn `Uthaymin (may Allah have mercy on him) said:
“The belief of the Salaf (righteous predecessors) concerning the Quran is like their belief in all the Names and Attributes of Allah, which is a belief that is based on what is indicated by the Book of Allah and the Sunnah (traditions) of His Messenger (peace and blessings be upon him). 
We all know that Allah, may He be Glorified and Exalted, has described the Quran as being His Word and that it was sent down from Him. Allah, may He be Sxalted, says (interpretation of the meaning):
“And if any of the polytheists seeks your protection then grant him protection, so that he may hear the Word of Allah (the Quran), and then escort him to where he can be secure.” [At-Tawbah 9:6]
Undoubtedly what is meant by the Word of Allah here is the Noble Quran .
And He, may He be exalted, says:
“Verily, this Quran narrates to the Children of Israel most of that about which they differ.” [An-Naml 27:76]
So the Quran is the Word of Allah in both wording and meaning. Allah spoke it in a real sense and gave it to Jibril (peace be upon him) the trustworthy, then Jibril brought it down to the heart of the Prophet (peace and blessings of Allah be upon him), so that he might be one of the warners, in a plain Arabic tongue. 
The Salaf believe that the Quran was revealed ; Allah, may He be Glorified and Exalted, revealed it to Muhammad (peace and blessings of Allah be upon him) piecemeal, i.e., bit by bit, over twenty-three years, in accordance with the Wisdom of Allah, may He be Glorified and Exalted. 
Moreover, some of the revelation was revealed for a specific reason for which it was sent down, and some of it was revealed without a specific reason. Moreover, some of it was revealed to tell of something that happened to the Prophet (peace and blessings of Allah be upon him) and his companions. Some of it was revealed concerning Shar`i (legal) rulings, according to what the scholars have said concerning this matter. 
Then the Salaf say that the Quran is from Allah in the first place and it will return (to Him) at the end of time. This is the view of the Salaf concerning the Noble Quran. 
It is clear to us that Allah has described the Noble Quran in superlative terms. He has described it as wise (Hakim), noble (Karim), great (`Adhim), and glorious (Majid). 
These qualities, in terms of which Allah has described His Book, may be attainable by one who adheres to this Book and acts upon it both inwardly and outwardly. Allah will give him some share of glory, greatness, wisdom, honour and authority that is not given to the one who does not adhere to the Book of Allah, may He be Glorified and Exalted. 
Hence I call all Muslims, rulers and ruled, scholars and ordinary folk, to adhere to the Book of Allah, may He be Glorified and Exalted, both inwardly and outwardly, so that they may attain honour, happiness and glory, and prevail in the east and in the west.” (Fatawa Kibar `Ulama Al-Ummah)
And Allah knows best.