Musannaf Ibn Abi Shayba 13:2388

Abu Bakr narrated to us, he said: Al-Thaqafi narrated to us, from Ayyub, from Ibn Sirin, that he used to dislike that a man should hand over goods to a man as a *mudarabah* (profit-sharing partnership) while he holds him accountable for a dirham (i.e., guarantees the capital against loss).