Musannaf Ibn Abi Shayba 13:1621

Abu Bakr narrated to us, he said: Mu'tamir ibn Sulayman narrated to us, from Kathir ibn Nabata, from al-Hakam ibn Aban, from Tawus: That he did not see any harm in a man standing over a man’s goods and handing them over to him as a *mudaraba* (profit-sharing partnership) based on that value.