Musnad Ahmad 27:1497

Aswad and Husayn narrated to us, they said: Sharik narrated to us, from Mu'awiyah ibn Ishaq, from Abu Salih, from a man among the companions of the Prophet, may Allah bless him and grant him peace—I think it is Ibn Umar—who said: I heard the Prophet, may Allah bless him and grant him peace, saying: "Whoever mutilates a living being, then does not repent, Allah will mutilate him on the Day of Resurrection." Husayn said: "Whoever mutilates a living being."