Musannaf Ibn Abi Shayba 13:1433

Abu Bakr narrated to us, he said: Abd al-Wahhab al-Thaqafi narrated to us, from Khalid, from Iyas ibn Mu'awiyah, regarding the boy whom a man hands over to another man to teach him, then he takes him out before his stipulated term has expired. He said: He shall return to his teacher what he spent on him.