Musnad Abu Ya'la al-Mawsili 119:2

Abu Khaythama Zuhayr ibn Harb narrated to us, Ibn Abi Uways Isma'il narrated to us, my father narrated to me, from Sharik ibn Abi Namir, from Anas ibn Malik, who said: A man traveled with the Prophet, may Allah bless him and grant him peace, and he cursed his camel. The Prophet, may Allah bless him and grant him peace, said: "O servant of Allah, do not travel with us on a cursed camel."