(1) باب كَيْفَ نُزُولُ الْوَحْىِ وَأَوَّلُ مَا نَزَلَ
Narrated `Aisha and Ibn `Abbas:
The Prophet (ﷺ) remained in Mecca for ten years, during which the Qur'an used to be revealed to him; and he stayed in Medina for ten years. (ID)
Reference (ID): Sahih al-Bukhari 4978, 4979 (ID)
In-book reference (ID): Book 66, Hadith 1 (ID)
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 6, Book 61, Hadith 502 (ID)