Volume 7 · Book 61 · Hadith 502
Narrated 'Aisha and Ibn 'Abbas: The Prophet 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.
— Sahih Bukhari, Volume 7, Book 61: Virtues of the Qur'an, Hadith #502