Musannaf Ibn Abi Shayba 13:3201

Abu Bakr narrated to us, he said: Mu'tamir ibn Sulayman narrated to us, from Salm ibn Abi al-Dhayyal, who said: I asked al-Hasan about two men who bought merchandise, then sold it, and made a profit in cash and credit. One of them said to his companion: "Give me my capital, and whatever remains is yours." He said: Al-Hasan disliked that.