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 No. 1211
Sunan an Nasai
Gradings:
Abu Ghuddah:
Daif Isnaad
Al-Albani:
Daif Isnaad
Zubair Ali Zai:
Daif