As the prophet approached the age of 40, he started meditating in the cave of Hira, where he would spend time in worship and solitude.
One such day when the Holy prophet was meditating in the cave of Hira, the Angel Gabriel came to Him and commanded to read.
The Prophet (P.b.u.h) replied that he could not read, the angel then hugged him tightly and asked him again to read. This was repeated once more after which the angel recited the folloeing verses of Surah Alaq.
“Read in the name of your Lord who created. Created man from a clot of blood. Read your Lord is most generous / bountiful. He who taught man with the pen. Taught man what he did not know.”
Holy Prophet (P.b.u.h) recited these verses after the angel and the words were imprinted on his mind.
In confusion the Prophet (P.b.u.h) ran out of the cave . outside he saw the angel filling the horizon and then he heard a voice. “O Muhammad You are the messenger of Allah and I am Jibrael”
The prophet (P.b.u.h) ran to his house and asked Hazrat Khadija to cover him up in a blanket.
He then narrated the entire incident to her.
On hearing the entire incident Hazrat Khadija comforted him by saying
“You have never done any wrong to anyone. You are kind to others and help the poor Allah will not let you down. ”
Hazrat Khadija then later took him to her cousin Warqah Bin Naufil. Warqah confirmed the prophet hood of the prophet and said that he had been visited by the same angel who had visited other prophets. He also forewarned that the prophet will be expelled from his own city by his own people.
Later Allah sent another revelation to Prophet Muhammad (P.b.u.h):
“O you who wrapped up (in a mantle)! Arise and deliver thy warning! And thy Lord do though Magnify”
“And warn your relatives”
So the prophet started preaching secretly to people who were close to him, his relatives and friends.
First people to accept Islam were:
His wife – khadija (first person also first woman to accept Islam)
His cousin – Ali (youngest person as he accepted Islam at the age of 10.)
His friend – Abu Bakr (first free male to accept Islam)
His slave – Zayd Bin Haritha (first slave to accept Islam)
Call at Safa:
Later Prophet Muhammad (P.b.u.h) assembled people of Makkah at Saffa and announced to the Makkans that they should accept that there was no god but Allah. This announcement greatly upset them and they turned away.