Muhammad (S.A.W.) was born in Makkah about 570 C.E. into the clan of Banu Hashim of the Quraysh. Before prophethood he was known for truthfulness and trustworthiness, earning the title al-Amin (the trustworthy).
Preparation. As he grew, he became distressed by the idolatry, injustice and corruption of Makkan society. He began to withdraw for meditation to the cave of Hira on the Mountain of Light (Jabal an-Nur) outside Makkah, spending days in reflection and worship of the One God.
The first revelation. In the month of Ramadan, when he was about forty years old, the Angel Jibril (Gabriel) came to him in the cave and commanded, "Iqra’" (Read/Recite). Muhammad replied that he could not read. The angel embraced him firmly three times and then revealed the first verses of Suratul-‘Alaq: "Read in the name of your Lord who created; created man from a clot..." (Q96:1-5).
His reaction. Trembling with awe, he hurried home to his wife Khadijah and asked to be covered. She comforted and reassured him. She took him to her cousin Waraqah bin Nawfal, a learned Christian, who recognised that this was the same great angel (an-Namus) that had come to Musa, and confirmed that Muhammad had been chosen as a prophet.
Confirmation and the call. Revelation paused for a time (fatrat al-wahy), then resumed with Suratul-Muddaththir: "O you who are wrapped up, arise and warn" (Q74:1-2), commissioning him to convey the message. Thus Muhammad became the Prophet and Messenger of Allah, first preaching secretly, then openly, calling people to worship the One God.
His prophethood was the seal of prophethood (Khatam an-Nabiyyin), Q33:40.