Musannaf Ibn Abi Shayba 13:2400

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Sufyan narrated to us, from Abu Ishaq, from Shurayh, that he used to not return [an animal] due to stumbling, and he would say: "All beasts stumble." And Waki’ said: Sufyan said: "It is a defect for which it is returned."