مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3520
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn ‘Abbas (رضي الله عنه) said: The first one who prayed with the Prophet (ﷺ) after Khadeejah was ‘Ali. And on one occasion he said: (The first one who) became Muslim.
Musnad Ahmad 3542Its isnad is da’feef]