Musannaf Ibn Abi Shaybah

Ibrahim says regarding the woman who buys her father and then frees him, and then the father dies while one of her sisters is alive, that for both of them there are two-thirds of the wealth according to the Book of Allah, and for this woman the remaining one-third because she is 'asabah (residuary heir). Abu Bakr says that in my view, this opinion is the most correct.