مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2740
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from Ibn 'Abbas (رضي الله عنه), who attributed it to the Prophet (ﷺ): "If a man's slave woman bears him a child, she becomes free when he dies.” Or he said: "after he dies.”
Musnad Ahmad 2759Hasan; this is a da'eef isnad]