Musannaf Ibn Abi Shayba 28:1148

Abu Khalid al-Ahmar narrated to us, from ‘Amr ibn Qays, from Mughirah ibn Ziyad, from Makhul, from ‘Ubadah ibn Nusayy, who said: Abu Bakr said: "Do not slaughter an animal, even if it becomes exhausted."