Musnad Ahmad 5:680

Abdullah narrated to us, Shayban Abu Muhammad narrated to us, Abd al-Warith ibn Sa'id narrated to us, al-Hasan ibn Dhakwan narrated to us, from Amr ibn Khalid, from Habib ibn Abi Thabit, from Asim ibn Damrah, from Ali, from the Prophet, peace and blessings of Allah be upon him, who said: "Gabriel, peace be upon him, came to me but did not enter." The Prophet, peace and blessings of Allah be upon him, said to him: "What prevented you from entering?" He said: "We do not enter a house in which there is an image or urine."