Musannaf Ibn Abi Shayba 19:189

Abu Bakr narrated to us, he said: Hatim ibn Isma'il narrated to us, from Ja'far, from his father, who said: 'Ali would not exceed cutting off a hand and a foot for a thief. If he was brought to him after that, he would say: "I am indeed ashamed that he should not be purified for his prayer, but withhold all of him from the Muslims, and spend upon him from the public treasury (Bayt al-Mal)."