Islam would have its beginnings with the prophet Muhammad, a direct descendent of Ishmael, in Arabia. Muhammad was born in 570 in Mecca, an ancient city in southwestern Arabia where he lived as a shepherd and a merchant for most of his life. After becoming tired of how he was living, Muhammad moved into the wilderness and began meditating in a cave, reflecting on life. It was here, at the age of forty, that God gave him his first revelation through the angel Gabriel. During this time for about twenty years, God continued to reveal through Gabriel many more revelation to him of which his followers began to memorize as he dictated it to them. This is now known as the Qur'an today.
Visions in the Desert : The Revelation of Muhammad Part 1