Did the Righteous Caliphs commit murder and mutilation, and is any act they did considered a Sunnah to be followed, even if it was a precedent?

Mutilation (al-Muthlah) is a punishment involving disfiguring the creation or severing limbs. The Prophet, peace and blessings be upon him, forbade it except as a form of retaliation (qisas) or an eye for an eye, based on the Almighty's saying: (And if you punish, then punish with the like of that with which you were punished). Some Companions permitted mutilation in rare instances for a legitimate Sharia interest. The Prophet, peace and blessings be upon him, commanded following his Sunnah and the Sunnah of the Rightly Guided Caliphs. Their Sunnah encompasses their general methodology and conduct in adhering to the Prophet's Sunnah, what they issued as fatwas or ruled upon in specific, جزئي (partial) matters, and what no Companion was known to have contradicted, which then becomes a proof.