مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2317
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn 'Abbas (رضي الله عنه) said: I stood with the Prophet (ﷺ) to pray, on his left, and he made me stand on his right.
Musnad Ahmad 2325Its isnad is saheeh]