Sayyiduna Abu Bakr (may Allah be pleased with him) intended to cut off a man's foot after his hand and foot had already been cut off, and Sayyiduna Umar (may Allah be pleased with him) said: "The Sunnah is the hand." The saying of Sayyiduna Umar (may Allah be pleased with him), "The Sunnah is the hand," suggests that he knew a Sunnah of the Messenger of Allah (peace and blessings be upon him) concerning it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السرقة / 17264