Sa'id bin al-Musayyab narrates: We have preserved from thirty Companions, from the Prophet (peace and blessings be upon him), that he said: "Whoever frees his share in a slave will be liable (to the other owners) for the rest of his value."
Imam Ahmad recorded this narration; its chain contains a narrator, al-Hajjaj bin Artah, who is thiqah (trustworthy), but he is a mudallis (one who practises tadlis); the remaining narrators of this narration are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب العتق / 7288