Sunan an-Nasa'i 1213

Al-Qasim ibn Zakariyya ibn Dinar reported to us; he said: Abu Usamah reported to us; he said: Shurahbil—meaning Ibn Mudrik—narrated to me; he said: ‘Abd Allah ibn Naji narrated to me, from his father, who said: ‘Ali said to me: I held a position with the Messenger of Allah (ﷺ) that no one among all creation held. I would come to him every dawn and say, “Peace be upon you, O Prophet of Allah.” If he cleared his throat, I would return to my family; otherwise, I would enter to see him.