570
Musnad AhmedIt was narrated that "Abdullah bin Nujayy said:
"Ali said: There was a time before dawn when I would ask to enter upon the Messenger of Allah (ﷺ). If he was praying, he would say Subhan Allah to me, and that was my permission to enter; if he was not praying, he would give me permission to enter.
Reference: Musnad Ahmad 570
Arabic/English book : Book 5, Hadith 570
Arabic/English book : Book 5, Hadith 570