The Holy Qur’an was compiled piece by piece over a number of years 1400 years ago, by the Prophet Muhammad (SAW) and his Companions (RAA) (the first early Muslims.) The Angel Gabriel brought verses of the Qur’an to the Prophet (SAW) , who would memorize them. Afterwards, they was preserved in two ways: A) through writing them down, and B) through memorizing them. Whenever any revelation took place, it was written down immediately on tablets, palm branches, shorn of leaves, or animal skin. This was done largely by the main scribe Zaid bin Thabit (RAA) .The Prophet (SAW) would set the order of the verses under the guidance of Angel Gabriel and ordered his companions to maintain that order. Abu Bakr (RAA) , the first caliph of Islam, compiled the Qur’an, and Uthman (RAA) , the third caliph, made numerous copies and sent one copy to each state capital to spread the message of Islam.
Ever since then, the Qur’an has not been changed in the slightest & has remained miraculously untouched for 1400 years. It is the most widely read and memorized book in the world. Even now, scientific discoveries are being about the world and the universe we live in that had been revealed in the Qur’an long ago. This is what makes the Qur’an the greatest miracle.
The tradition of memorizing the Qur’an also continues to this day. Muslims even follow the same steps to memorizing the Holy Qur’an as the Prophet (SAW) , by memorizing the Qur’an bit by bit until they have learned the whole thing by heart. And the rewards for doing so are mighty, as whosoever memorizes and acts upon the Qur’an will be shielded by it from the hellfire and will be raised in status in paradise.