كتاب الصلاة
4  
The Book of Prayers
(22)
Chapter: The Congregation Appointing Someone To Lead Them If The Imam Is Delayed And If There Is No Fear Of Negative Repercussions
(22)
باب تَقْدِيمِ الْجَمَاعَةِ مَنْ يُصَلِّي بِهِمْ إِذَا تَأَخَّرَ الإِمَامُ وَلَمْ يَخَافُوا مَفْسَدَةً بِالتَّقْدِيمِ
Sahih Muslim 421 c

Sahl b. Sa'd al-Sa'idi reported:

The Apostle of Allah (ﷺ) went to Bani Amr b. 'Auf in order to bring about reconciliation amongst them. The rest of the hadith is the same but with (the addition of these words):" The Messenger of Allah (ﷺ) came and made his way through the rows till he came to the first row and Abu Bakr retraced his steps."
حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ بَزِيعٍ، أَخْبَرَنَا عَبْدُ الأَعْلَى، حَدَّثَنَا عُبَيْدُ اللَّهِ، عَنْ أَبِي حَازِمٍ، عَنْ سَهْلِ بْنِ سَعْدٍ السَّاعِدِيِّ، قَالَ ذَهَبَ نَبِيُّ اللَّهِ صلى الله عليه وسلم يُصْلِحُ بَيْنَ بَنِي عَمْرِو بْنِ عَوْفٍ ‏.‏ بِمِثْلِ حَدِيثِهِمْ وَزَادَ فَجَاءَ رَسُولُ اللَّهِ صلى الله عليه وسلم فَخَرَقَ الصُّفُوفَ حَتَّى قَامَ عِنْدَ الصَّفِّ الْمُقَدَّمِ ‏.‏ وَفِيهِ أَنَّ أَبَا بَكْرٍ رَجَعَ الْقَهْقَرَى ‏.‏
Reference : Sahih Muslim 421c
In-book reference : Book 4, Hadith 113
USC-MSA web (English) reference : Book 4, Hadith 847
  (deprecated numbering scheme)