(25) باب اسْتِقْضَاءِ الْمَوَالِي وَاسْتِعْمَالِهِمْ
Narrated Ibn `Umar:
Salim, the freed salve of Abu Hudhaifa used to lead in prayer the early Muhajirin (emigrants) and the companions of the Prophet (ﷺ) in the Quba mosque. Among those (who used to pray behind him) were Abu Bakr, `Umar, Abu Salama, and Amir bin Rabi`a.
Reference: Sahih al-Bukhari 7175
In-book reference: Book 93, Hadith 39
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 9, Book 89, Hadith 287