Musannaf Ibn Abi Shayba 18:1184

Abu Bakr narrated to us, he said: Muhammad bin Bakr narrated to us, from Ibn Jurayj, he said: Hisham bin Abd al-Malik judged regarding the slave of Ayyub, the freedman of Nafi, with fifty oaths upon Ayyub. So he swore, and he took his price.