The Book of Allaah containing His Words revealed to the Trusted One on the Earth, Muhammad , through the medium of the Trusted One in the Heaven, Jibraa`eel (AS). It was revealed piecemeal to the Prophet Muhammad  over a period of twenty-three years and some months. Allaah says,

"We have rehearsed it to you gradually in well-arranged stages." [al-Furqaan (25):32]

The first revelation which the Messenger of Allaah  received was,

"Read in the name of your Lord Who created. Created man from a clot (of coagulated blood). Read! And your Lord is the Most Generous." [al-`Alaq (96):1-3]

The last verse to be revealed after which no further verses containing new rules and regulations were revealed was,

"This day have I perfected your religion for you, completed My favour upon you and have chosen for you Islaam as your religion." [al-Maa`idah (5):4]

The last verse to be revealed was,

"And fear the Day when you shall be brought back to Allaah. Then every soul shall be paid what it earned and none shall be dealt with unjustly." [al-Baqarah (2):281]

The Qur`aan was collected under the auspices of the Prophet  in an order different from the chronological order of revelation. It consists of one hundred and fourteen chapters commencing with Surah al-Faatihah and ending with Surah an-Naas.

"Indeed the Book of Allaah is a deep and profound ocean (of knowledge and wisdom) and understanding it is a fine and delicate matter. No one can understand it correctly save one who has excelled in the (Islaamic) sciences and acts with taqwaa of Allaah both in the secret and in the open and is preserved from doubts and deviancy. No one can truly understand the Qur`aan except for one who pays devout attention with his heart present." - ‘al-Burhaan’ [2/154] of az-Zarkashee

"The foundation for studying the meaning of the Qur`aan is to ponder and reflect. Know that the one reflecting can never attain true understanding of the Revelation and neither will the secrets of knowledge be manifested to him if his heart contains innovation or he persists in committing a sin, or his heart contains arrogance, or submission to his base desires, or love of this world, or he has not realised the reality of faith, or his faith is weak, or he bases his understanding only upon what his intellect comprehends. All of these factors serve as barriers from understanding the Qur`aan and some are more severe than others." – ‘al-Burhaan’ [2/180-181]