Musannaf Ibn Abi Shayba 13:1336

Abu Bakr narrated to us, he said: Jarir narrated to us, from Mughira, from Hammad, who said: If the *mudarib* (manager of the profit-sharing partnership) wishes, he may hire a worker and feed the slave, if it is from the *mudaraba* (capital). And he shall not eat with them.