مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2109
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) used to manumit any slaves who came to him, if they became Muslim before their masters, and on the day of at-Ta'if he manumitted two men.
Musnad Ahmad 2111Hasan because of corroborating evidence, this is a da'eef is