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, ʿUmar, Abu Salama, and Amir bin Rabiʿa.  

أَخْبَرَهُ قَالَ كَانَ سَالِمٌ مَوْلَى أَبِي حُذَيْفَةَ يَؤُمُّ الْمُهَاجِرِينَ الأَوَّلِينَ وَأَصْحَابَ النَّبِيِّ ﷺ فِي مَسْجِدِ قُبَاءٍ فِيهِمْ أَبُو بَكْرٍ وَعُمَرُ وَأَبُو سَلَمَةَ وَزَيْدٌ وَعَامِرُ بْنُ رَبِيعَةَ