Musannaf Ibn Abi Shayba 19:506

Abu Bakr narrated to us, he said: Humayd ibn Abd al-Rahman narrated to us, from Hasan ibn Salih, from Ghalib Abu al-Hudhayl, he said: I heard Subay' Abu Salim saying: I witnessed al-Hasan ibn Ali, and a man was brought to him who had confessed to theft. Al-Hasan said to him: "Perhaps you snatched it?" so that he might say: "No."