Bayhaqi 21353 — One who frees his share in a jointly owned slave

Al-Rabi' says: Imam al-Shafi'i (may Allah have mercy on him) said to someone debating with him: Is there any room for debate once the Sunnah of the Messenger of Allah (peace and blessings be upon him) is established, in the hadith of Nafi' from Ibn Umar, that having the slave work to pay off his remaining value (istis'a') is dropped? He said: We say that Ayyub said: Sometimes Nafi' said, "then as much of him is freed as was freed," and sometimes he did not say it; and he said: My strongest belief is that it was something Nafi' used to say from his own opinion. Imam al-Shafi'i (may Allah have mercy on him) said: I said to him: I do not think anyone who knows hadith and its narrators doubts that Malik preserved the hadith of Nafi' better than Ayyub, because he kept closer company with him than Ayyub did, and Malik has a special excellence in preserving the hadith of his own teachers in particular. Even if the two were equal in memory, and one of them doubted something the other did not doubt, that would be no ground for declaring the one who did not doubt mistaken. A man is only declared mistaken when someone with a better memory contradicts him, or when he brings something in a hadith that others share with him who did not preserve from it what he preserved, they being many and he alone. Others have agreed with Malik on the addition: "otherwise, as much of him is freed as was freed." And some of them added to it: "and as much of him remains a slave as remains enslaved."
Al-Shaykh (may Allah have mercy on him) said: As for the hadith of Ayyub, we have mentioned it earlier.