Musannaf Ibn Abi Shayba 13:10

Waki’ narrated to us, he said: Sufyan narrated to us, from Abu Husayn, from Ali, regarding the *mudaraba* (profit-sharing partnership) or the two partners—Sufyan said: "I do not know which of the two he said"—: The profit is according to what they have agreed upon, and the loss is upon the capital.