Sunan An-Nasa'i

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