Musnad Ahmad 5:606

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from 'Ali ibn Mudrik, from Abu Zur'ah, from 'Abdullah ibn Naji, from his father, from 'Ali, from the Prophet, peace and blessings of Allah be upon him, who said: "The angels do not enter a house in which there is an image, nor a person in a state of major ritual impurity (junub), nor a dog."