What was the beginning of Revelation to the Messenger of Allah salla alayhi wa sallam

 Urwah bin Zubair reported that Aishah, wife of the Prophet salla alayhi wa sallam, told him that the revelation to the Messenger began with the true vision in his sleep. Whenever he saw a dream, its interpreation came as clear as the break of dawn. Then he was made to love seclusion. He used to seclude himself in Cave Hira´ to stay there a number of nights contemplating before he returned to his family. Then he would return to Khadijah and take provision and go back again until when suddenly the Truth came to him while he was in the cave of Hura´.

The angel came to him and asked him to read. He said, ´´I cannot read.´´ The Prophet salla alayhi wa sallam added, ´´Then the angel hugged me and pressed me hard that I became exhausted. He then released me and again asked me to read and I replied, ´I cannot read.´

Thereupon he hugged me again and pressed me a second time until I was exhausted. He then released me and again asked me to read but again I replied, ´I cannot read (or what shall I read)?´ Thereupon he caught me for the thirds time and pressed me, and then released me and said, ´Read with the Name of your Rubb, Who has created. 

Created man from a thing which clings. Read! and Your Rubb is the Most Generous, Who has taught by the pen. He has taught man what he did not know.´ (V96:1-5).´´

Then Allah´s Messenger salla alayhi wa sallam returned with the Revelation and his body was trembling. Then he went to Khadijah and said, ´´Wrap me up! Wrap me up!´´ They wrapped him until his fear departed. He said to Khadijah, ´´O Khadijah, what has happened to me?´´ And he informed her what had happened (and said), ´´I was worried about myself (being unable to handle the responsibility).´´

Khadijah replied, ´´Never Rejoice. I swear by allah, allah will never disgrace you. By Allah, you keep good relations with your kith and kin, you speak the truth, bear people´s burden, help the poor and the needy, serve your guests generously and assist the deserving calamity-aflicted ones.´´

Khadijah then accompanied him to her cousin Waraqah bin Naufal bin Asad bin Abdul-Uzza, who, during the Period of Ignorance became a Christian, and used to write the writing with Arabic letters. He used to write from the Gospel in Arabic as much as Allah willed. He was an old man and had lost his eyesight.

Khadijah said to him, ´´Listen to the story of your nephew, O my uncle.´´ Waraqah bin Naufal asked, ´´O my nephew! What have you seen?´´ The Messenger of Allah salla alayhi wa sallam described whatever he had seen. Waraqah said, ´´This is the same angel whom Allah sent to Moses bin ´Imran. I wish I were young and could live up to the time when your people will drive you out.´´

The Messenger of Allah salla alayhi wa sallam asked, ´´Will they drive me out?´´ Waraqah replied in the affirmative and said, ´´No man came with something similar to what you have brought but was treated with hostility; and if I survive until that day then I will support you strongly.´´