Musnad Ahmad 32:1102

Al-Walid ibn Muslim narrated to us, Al-Awza’i narrated to us, he said: Yahya ibn Abi Kathir narrated to me, he said: Abu Qilabah al-Jarmi narrated to me, from Anas ibn Malik, who said: Eight men from ‘Ukl came to the Prophet, may Allah bless him and grant him peace, and they accepted Islam, but the climate of Medina did not agree with them. So the Messenger of Allah, may Allah bless him and grant him peace, ordered them to go to the camels of charity and drink from their urine and their milk. They did so and recovered. Then they apostatized, killed their shepherds—or their herders—and drove them [the camels] away. The Messenger of Allah, may Allah bless him and grant him peace, sent trackers in pursuit of them. They were brought, and he cut off their hands and their feet, and he did not cauterize them until they died, and he gouged out their eyes.