مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3110
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
Sulaiman ash-Shaibani said: I heard ash-Sha'bi say: One who passed with the Messenger of Allah (ﷺ) by a grave that was separate from others told me that he led them in prayer and they formed rows behind him. I said: O Abu 'Amr, who told you that? He said: Ibn 'Abbas.
Musnad Ahmad 3134Its isnad is saheeh, al-Bukhari (857) and Muslim (954)]