مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2387
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from Ibn ‘Abbas (رضي الله عنه) that The Messenger of Allah (ﷺ) stayed in Makkah for fifteen years, during seven or eight of which he would see a light and hear a voice, and during seven or eight of which revelation came to him. And he stayed in Madinah for ten years.
Musnad Ahmad 2399Its isnad is qawi, Muslim (2353)]