(Imam Bukhārī said:) Yaḥyā bin Bukayr narrated to us, he said: Al-Layth narrated to us, from ʿUqayl, from Ibn Shihāb, from ʿUrwa bin al-Zubayr, from Hazrat ʿĀʾisha, the Mother of the Believers (may Allāh be pleased with her), she narrates that

The first thing with which revelation began upon the Messenger of Allāh ﷺ was true dreams (shown) in sleep. Whatever dream he saw, its interpretation would come true like the bright morning. Then love of solitude was placed within him. He would go to the cave of Hira in solitude and worship there for many nights before returning home. He would take food items there for his stay, then he would return to Hazrat Khadīja, and then he would take food items again in the same way, until revelation came to him. At that time he was in the cave of Hira. The angel came to him and said: "Read." He [the Messenger of Allāh ﷺ] said: "I am not to read." He ﷺ says: So he caught hold of me and squeezed me so hard that I suffered extreme hardship, then he released me. He [angel] said again: "Read." I said: "I am not to read." He caught me a second time and squeezed me so hard that I suffered extreme hardship, then he released me and said: "Read." I said: "I am not to read." So he caught me and squeezed me a third time so hard that I suffered extreme hardship, then he released me, then said: "(O Honored Messenger!) Read in the name of your Lord who created (you). Created man from clotted blood. Read and your Lord is the Most Generous." (Al-Alaq: 1-3) The Messenger of Allāh ﷺ read these verses, then returned home in a state that his heart was trembling. He came to Hazrat Khadīja bint Khuwailid (may Allah be pleased with her) and said: "Cover me! cover me!" So the family covered him, until when his fear went away, he informed Hazrat Khadīja of the incident and said: "I fear for myself." Hazrat Khadīja said: "Never! By Allāh! Allāh will never disgrace you. You keep ties with relatives, carry the burden of the weak, earn for those who have nothing, honor guests, and help in the difficulties that come in the path of truth." Then Hazrat Khadīja took him, until they reached Waraqah bin Naufal bin Asad bin Abdul Uzza, who was Hazrat Khadīja's cousin. He had become a Christian in the Age of Ignorance, he used to write books in the Hebrew language; so he used to write the Injeel in Hebrew as much as Allāh willed. He was very old and had become blind. Hazrat Khadīja said to him: "O my cousin! Listen to your nephew." Waraqah said to him: "O nephew! What do you see?" Then the Messenger of Allāh ﷺ told him what he had seen. Waraqah said: "This is the same bearer of secrets (the angel who brings the message) [Jibrīl] that Allāh sent down upon Musa. I wish I were young at that time! I wish I were alive at that time, when your people will expel you!" Then the Messenger of Allāh ﷺ said: "Will they expel me?" Waraqah said: "Yes! Whoever came with a message like yours, enmity was held against him. If that time finds me alive, I will help you very strongly." After that, Waraqah did not live many more days, and he passed away, and the descent of revelation paused.