Musannaf Ibn Abi Shayba 13:1470

Abu Bakr narrated to us, he said: Hafs narrated to us, from Sa’id, from Qatadah, from Sa’id ibn al-Musayyib, who said: Shurayh erred, even if he was a judge. Zayd ibn Thabit used to rule in favor of the debt before the *mukātabah* (contract of manumission).