Musannaf Ibn Abi Shayba 36:210

'Abd al-A'la narrated to us, from Dawud ibn Abi Hind, from al-Sha'bi, who said: When the day of Uhud arrived and the polytheists departed, the Muslims saw the terrible mutilation of their brothers. They began to cut off their ears and noses and slit their bellies. The companions of the Messenger of Allah (may Allah bless him and grant him peace) said, "If Allah grants us victory over them, we will surely do the same." Then Allah revealed: "And if you punish, punish with an equivalent of that with which you were harmed. But if you are patient - it is better for those who are patient." The Messenger of Allah (may Allah bless him and grant him peace) said, "Rather, we shall be patient."