Revelation began with true dreams that came to pass like the break of dawn. Then, at about the age of forty, while he was worshipping in the Cave of Hira, the angel Jibril came to him and said: "Read!" He replied that he was not a reader. After the angel pressed him three times, he recited the first verses revealed of the Quran: "Read in the name of your Lord who created…" (96:1–5).

He returned home trembling and said to Khadijah, "Cover me, cover me." When he told her what had happened, she reassured him: Allah would never disgrace him, for he kept ties of kinship, helped the weak, honoured guests and stood by people in hardship. She became the first person to believe in him.

Khadijah took him to her cousin Waraqah ibn Nawfal, an elderly man who knew the earlier scriptures. Waraqah recognised that this was the same angel who had come to Musa, and said he wished he would live to support him when his people drove him out.

Then revelation paused for a time. It resumed when he saw the angel again between the heavens and the earth and was commanded: "O you who are wrapped up, arise and warn" (74:1–5). From then on, revelation continued for twenty-three years.