Musnad Abu Ya'la al-Mawsili 3:90

Ubayd Allah narrated to us, Abd al-Rahman ibn Mahdi narrated to us, Sufyan narrated to us, from Habib ibn Abi Thabit, that Ali said to Abu al-Hayyaj: "Shall I not send you upon that which the Messenger of Allah (may Allah bless him and grant him peace) sent me upon? Do not leave any elevated grave except that you level it, and [do not leave] any statue except that you efface it."