Musnad Ahmad 26:618

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, he said: I heard Yahya ibn al-Mujabbar, he said: I heard Abu Majid—meaning al-Hanafi—he said: I was sitting with ‘Abdullah, and he said: I remember the first man whose hand was cut off. A thief was brought, and he [the Prophet] ordered his hand to be cut off, and it was as if the face of the Messenger of Allah (may Allah bless him and grant him peace) became distressed. He said: They said: "O Messenger of Allah, it is as if you disliked his cutting?" He said: "And what would prevent me? Do not be helpers to the Shaytan against your brother. It is necessary for the Imam, when a prescribed punishment (hadd) reaches him, to carry it out. Indeed, Allah the Almighty is Pardoning and loves pardon: '...and let them pardon and overlook. Would you not like that Allah should forgive you? And Allah is Forgiving and Merciful' [An-Nur: 22]."