Musannaf Ibn Abi Shayba 18:456

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Sufyan, from Tariq, from al-Sha’bi, who said: The crime of the slave is [attached] to his neck. His master is given the choice: if he wishes, he may ransom him, and if he wishes, he may surrender him.