مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1958
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn "Abbas said: On the day of at-Ta"if, the Messenger of Allah (ﷺ) freed all the slaves of the mushrikeen who came out to him.
Musnad Ahmad 1959Hasan because of corroborating evidence; this is a da'eef is