Musannaf Ibn Abi Shayba 13:1976

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Muhammad ibn Abi al-Ja’d, he said: I asked al-Sha’bi about buying the dust of the goldsmiths, and he disliked it and said: "It is *gharar* (uncertainty/risk)." Muhammad said: And my father used to buy it with trade goods.