Musannaf Ibn Abi Shayba 13:2818

Abu Bakr narrated to us, he said: Ibn ‘Ulayyah narrated to us, from Yunus, from Mutarrif ibn ‘Utbah, from his father—and he was a friend of Shurayh—he said: I said to Shurayh, "I go to the market and buy a garment, and I stipulate that I have the option [to return it] regarding it. Then I go, and if I sell it, I take the profit, and if not, I return it." He said: "Do not do that."