Musnad Ahmad #803

It was narrated that ‘Ali (رضي الله عنه) said: I used to come to the Messenger of Allah (ﷺ) every morning. If he cleared his throat, I would enter, and if he remained silent, I would not enter. He came out to me (on one occasion) and said: “Something happened last night. I heard some movement in the house, then I saw Jibreel (عليه السلام). I said: ‘What prevented you from entering the house?` He said: “In the house there is a dog.` I went in and I saw a puppy belonging to al-Hasan beneath a chair of ours. He said: “The angels do not enter a house if there are three things in it: a dog or an image or a person who is junub.`