Musannaf Ibn Abi Shayba 13:1620

Abu Bakr narrated to us, he said: Mu'adh ibn Mu'adh narrated to us, from Ash'ath, from al-Hasan, that he said regarding a man who handed over goods to a man for *mudarabah* (profit-sharing partnership), and they appraised them between themselves: The capital is what the goods were appraised at, and their (original) value is nothing.