Musannaf Ibn Abi Shayba 19:118

Abu Bakr narrated to us, he said: Abu al-Ahwas narrated to us, from al-A'mash, from al-Qasim ibn Abd al-Rahman, from his father, who said: I was sitting with Ali when a man came and said: "O Commander of the Faithful, I have stolen." He rebuked him. Then he returned a second time and said: "I have stolen." Ali said to him: "You have testified against yourself twice." He said: So he ordered him [to be punished], and his hand was cut off. I saw it hanging, meaning around his neck.