Musannaf Ibn Abi Shayba 13:1335

Abu Bakr narrated to us, he said: Hafs narrated to us, from Ash'ath, from al-Hakam and Hammad, from Ibrahim, who said: The *mudarib* (manager of a profit-sharing partnership) spends and clothes himself according to what is customary. If there is profit, it is from his profit, and if there is a loss, it is from the capital. He said: And I asked Ibn Sirin, and he said: I do not like for him to spend until he seeks permission from the owner of the capital.