مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2826
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn ‘Abbas (رضي الله عنه) said: The Messenger of Allah (ﷺ) stayed in Makkah for fifteen years, seven years during which he saw a light and heard a voice, and eight years during which Revelation came to him. And he stayed in Madinah for ten [years].
Musnad Ahmad 2846Its isnad is saheeh, Muslim (2353)]