Hadith 1212
´It was narrated that 'Ali said:` "I had certain times when I used to come to the Messenger of Allah (ﷺ). When I came to him I would ask for permission to enter. If I found him praying he would clear his throat and I would enter, and if I found him free he would give me permission (to enter)."
Hadith 1213
´It was narrated that 'Ali said:` "I had two times when I would enter upon the Messenger of Allah (ﷺ), one at night and one during the day. When I entered at night he would clear his throat (to tell me to come in)."