From Sahih Bukhari (Hadith 7175):
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: Bukhari 7175