Musnad Ahmad 5:282

'Abd al-Razzaq narrated to us, Sufyan informed us, from Jabir, from 'Abd Allah ibn Naji, from 'Ali, who said: I used to come to the Messenger of Allah (peace and blessings of Allah be upon him) every morning. If he cleared his throat, I would enter, and if he remained silent, I would not enter. He said: So he came out to me and said: "An event occurred last night. I heard a rustling in the house, and behold, it was Gabriel (peace be upon him). I said: 'What prevented you from entering the house?' He replied: 'There is a dog in the house.'" He said: So I entered, and behold, there was a puppy belonging to al-Hasan under a chair of ours. He said: Then he said: "Indeed, the angels do not enter a house if there are three things in it: a dog, or an image, or a person in a state of major ritual impurity (junub)."