Musannaf Ibn Abi Shayba 13:1980

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Sufyan, from ‘Abdullah ibn Rabah, from Abu ‘Amr al-Shaybani, that a man found a runaway slave at ‘Ayn al-Tamr and brought him. Ibn Mas’ud set [a reward of] forty dirhams for him.