Hazrat Amr bin Shu'ayb (may Allah have mercy on him) reports from his father, from his grandfather (may Allah be pleased with him), that al-As bin Wa'il made a bequest that a hundred slaves be freed on his behalf. His son Hisham (may Allah be pleased with him) freed fifty slaves, and his other son Amr (may Allah be pleased with him) also intended to free the remaining fifty slaves, and said: "Let me first ask the Messenger of Allah (peace and blessings be upon him)." He came to the Prophet (peace and blessings be upon him) and said: "O Messenger of Allah (peace and blessings be upon him)! My father made a bequest that a hundred slaves be freed on his behalf; Hisham has freed fifty, and fifty remain. Shall I free them on his behalf?" The Messenger of Allah (peace and blessings be upon him) said: "If he was a Muslim, then free slaves on his behalf, or give charity, or perform Hajj, and it will reach him."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12637
Abd al-Rahman bin Abi Amrah al-Ansari (may Allah have mercy on him) reports from his mother (may Allah be pleased with her) that she intended to make a bequest, then postponed it until the morning; then she died, and she had intended to free a slave. Abd al-Rahman (may Allah have mercy on him) said to al-Qasim bin Muhammad (may Allah have mercy on him): If I free a slave on her behalf, will it benefit her? Al-Qasim (may Allah have mercy on him) said: Sa'd bin Ubadah (may Allah be pleased with him) said to the Messenger of Allah (peace and blessings be upon him): My mother has died; if I free a slave on her behalf, will it benefit her? The Messenger of Allah (peace and blessings be upon him) said: "Yes, free a slave on her behalf."
This is mursal (with a gap in the chain).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12638
It is reported from al-Hasan (may Allah have mercy on him) that Sayyiduna Sa'd (may Allah be pleased with him) came to the Prophet (peace and blessings be upon him) and said: "O Messenger of Allah! Umm Sa'd (may Allah be pleased with her) loved charity and loved freeing slaves. If I give charity on her behalf or free a slave, will she receive a reward?" He (peace and blessings be upon him) said: "Yes."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12639
Hazrat Aishah (may Allah be pleased with her) said that a man said: O Messenger of Allah! Should a slave be freed on behalf of my father? He (peace and blessings be upon him) said: "Yes."
This is how it was reported to us, and it is an error.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12640
It is narrated from Ata bin Abi Rabah that a man said: O Messenger of Allah (peace and blessings be upon him)! My father has died; should a slave be freed on his behalf? He (peace and blessings be upon him) said: "Yes."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12641
It is reported from Hazrat Aishah (may Allah be pleased with her) that her brother died in his sleep, and Hazrat Aishah (may Allah be pleased with her) freed on his behalf some of his long-held property (that is, slaves he had owned for a long time).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12642
Musa bin Salamah al-Hudhali said: I asked Ibn Abbas (may Allah be pleased with him): If a man frees a slave on behalf of his parents, will there be a reward for him? Ibn Abbas (may Allah be pleased with him) said: Yes.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12643