Aas bin Waail left instructions that one hundred slaves be freed on his behalf. His son Hisham freed fifty, then his son Amr wanted to free the remaining fifty on his behalf. Amr said, "Not until I ask the Messenger of Allah ﷺ."He came to the Prophet ﷺ and said, "Messenger of Allah, my father left instructions that one hundred slaves be freed, and Hisham has freed fifty on his behalf, leaving fifty more. Shall I free them on his behalf?"The Messenger of Allah ﷺ replied, "Had he been a Muslim, then your freeing slaves on his behalf, giving charity on his behalf, or performing Hajj on his behalf would have benefited him."
أن العاص بن وائل أوصى أن يعتق عنه مائة رقبة، فأعتق ابنه هشام خمسين رقبة، فأراد ابنه عمرو أن يعتق عنه الخمسين الباقية، فقال حتى أسأل رسول الله ﷺ، فأتى النبي ﷺ، فقال: يا رسول الله، إن أبي أوصى بعتق مائة رقبة، وإن هشاما أعتق عنه خمسين، وبقيت عليه حمسون رقبة أفأعتق عنه؟ فقال رسول الله ﷺ: إنه لو كان مسلما فأعتقتم عنه أو تصدقتم عنه أو حججتم عنه بلغه ذلك.
Abu Dawud (2883) narrated it from Abbas bin Walid bin Mazid, my father informed me, Uzai narrated to us, Hassan bin Atiya narrated to me, from Amr bin Shuayb, from his father, from his grandfather, and he related it.Its chain is hasan because of Amr bin Shuayb, for his hadith is hasan.Imam Ahmad (6704) also narrated it through this same route, from Hushaym, Hajjaj informed us, Amr bin Shuayb narrated to us, from his father, from his grandfather, except that it contains, "Aas bin Waail vowed during the Jahiliyyah to sacrifice a hundred camels, and Hisham bin Aas sacrificed his share, fifty camels, and Amr asked the Prophet ﷺ about that." He said, "As for your father, if he had affirmed the oneness of Allah, and you then fasted and gave charity on his behalf, that would have benefited him."Perhaps "raqabah" (a slave to be freed) was confused by some of the narrators, so he said "badanah" (a sacrificial camel) instead.Hajjaj is Ibn Artah, who is described as making frequent errors and practicing tadlis, and this may well be one of his errors. As for his tadlis, it is ruled out here, since he explicitly used the phrase "narrated to us."See the rest of the hadiths in the Book of Knowledge.