The Holy Quran was revealed to the Holy Prophet in parts from time to time spread over a period of 23 years. Whenever the Holy Prophet received the revelation. he would dictate it to one of his Katibs who would record it on some piece of leather, date skin, or even bones and stones.
The principal scribe of the Holy Prophet was Zaid bin Thabit. Many companions committed the entire Quran to memory and these 'Huffdz' could recite the entire Quran any time. The Holy Prophet kept all the pieces of leather, date skins another materials on which the verses of the Holy Quran had been written in his custody.
During the lifetime of the Holy Prophet, revelation was a continuous process, and there was no occasion for giving them the form of a book. After the death of the Holy Prophet, the process of revelation came to close, and now the need of some sort of compilation to preserve the Word of God was felt.
In the battle of Yamama, most of the Companions who had learnt the Holy Quran by heart were martyred. Umar was the first to feel that if those who had committed the Holy Quran to memory were dead, there was the danger that there would be none left who could be relied upon as the repository of the Quran. There was also the danger that with the lapse of time there might be some interpolations in the text inadvertently or even deliberately.
Umar suggested to the Caliph Abu Bakr that the Holy Quran should be suitably compiled under the authority of the State Abu Bakr was reluctant to undertake the project. His plea was that as the Holy Prophet had not felt the necessity for such a compilation, it did not behove him as the successor to the Prophet to take any initiative in the matter.
Umar, however, continued to press his point. Umar argued that during the lifetime of the Holy Prophet the process of revelation was continuous, and as the Holy Prophet himself was the repository of all revelations, there was no occasion for such a compilation. After the death of the Holy Prophet, the position had changed, and unless the Holy Quran was compiled, there was the danger that the Quran might be lost. In the absence ot an authentic text, there was also the danger that some unscrupulous persons might add to or vary the text to suit their interests. The argument appealed to Abu Bakr, and whe n other prominent Muslims were consulted, they also endorsed the views of Umar. Abu Bakr accordingly undertook the project for the compilation of the Holy Quran.
Zaid b. Thabit was commissioned by Abu Bakr to collect all the verses of the Holy Quran and compile them in a book form.
Zaid's immediate reaction to the proposal was that if he had been asked to remove a mountain from its original site, and place it elsewhere, he would have considered such a task easier than the task of collecting the Holy Quran. Abu Bakr and Umar appreciated the gravity of the problem, but observed that as the Word of God had to be preserved for the guidance of the coming generations, the task had to be undertaken whatever the odds. Zaid thereupon set to the task of collecting the verses.
A proclamation was made that whosoever had learnt any portion of the Quran from the Holy Prophet should produce such portion. Two witnesses had to be produced in each case to establish the genuineness of the verse. When all the verses had been collected a Committee was set up of which Umar was a member. This Committee supervised the compilation of the Holy Quran. Sad b. al As dictated, and Zaid bin Thabit wrote the Holy Quran. These was checked by the members of the Committee including Umar.
When the work was completed it was further checked by Abu Bakr, and the finally approved copy was kept by Abu Bakr in his personal custody. The sacred compilation was given the name of 'Mashaf'.
During his Caliphate, Umar took steps to ensure that the teaching of the Holy Quran was spread extensively, and that a large number of persons learnt the text by heart so that there could be no possibility of any corruption in the text.
Under the orders of Umar, hundreds of schools were opened throughout the length and breadth of the islamic world for the teaching of the Holy Quran. Highly qualified teachers were appointed for the purpose, and they were given good salaries.
Such Companions who had learnt the Holy Quran by heart were sent to distant places to teach the Holy Quran. Muadh b. Jabal; Ibada b al Samit; and Abu Darda were prominent companions who knew the Holy Quran by heart. They were sent to Syria where Ibada headed the school at Hims: Abu Darda at Damascus; and Muadh at Jerusalem. It is related that Abu Darda held his classes in the Jamia Masjid at Damascus and the enrolment in his class was 1600.
Umar took pains in promoting and popularising the study of the Holy Quran. All the Muslims were required to learn at least five Suras by heart. Special stipends were granted for the learning of the Holy Quran. In his instructions to the Army, Umar exhorted the men to read and memorise the Holy Quran.
Umar was very particular about the use of correct vowels and the correct pronunciation of the words in the Holy Quran. In his instructions to the teachers of the Holy Quran, Umar said:
"Teach them the vowels of the Quran, as you teach its learning by heart."
Umar also instructed that along with the teaching of the Holy Quran, the study of the Arabic language and literature should be made compulsory so that the readers of the Holy Quran should themselves be able to distinguish between right and wrong vowels.
Umar also laid down that no one who was not versed in Arabic lexicology should be permitted to teach the Holy Quran.