مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2679
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from 'A'ishah and Ibn 'Abbas (رضي الله عنهما) that The Messenger of Allah (ﷺ) stayed in Makkah for ten years, with Qur'an being revealed to him, then he stayed in Madinah for ten years.
Musnad Ahmad 2696lts isnad is saheeh, al-Bukhari (4464)]