Sunan an-Nasa'i 1213

Abdullah bin Nujayy narrated that his father said:"Ali said to me: 'I was so close to the Messenger of Allah (ﷺ), closer than anyone else. I used to come to him at the end of every night, before dawn, and say: "As-salamu 'alayka ya Nabiyy Allah (Peace be upon you, O Prophet of Allah)." If he cleared his throat I would go back to my family, otherwise I would enter upon him