Sahih al-Bukhari, Volume 1, Book 11, Hadith 651 (USC-MSA) ⓘ

Narrated Hisham ibn `Urwa's father: `Aisha said, "Allah's Messenger ordered Abu Bakr to lead the people in the prayer during his illness and so he led them in prayer." `Urwa, a sub narrator, added, "Allah's Messenger felt a bit relieved and came out and Abu Bakr was leading the people. When Abu Bakr saw the Prophet he retreated but the Prophet beckoned him to remain there. Allah's Messenger sat beside Abu Bakr. Abu Bakr was following the prayer of Allah's Messenger and the people were following the prayer of Abu Bakr."

حَدَّثَنَا زَكَرِيَّاءُ بْنُ يَحْيَى، قَالَ حَدَّثَنَا ابْنُ نُمَيْرٍ، قَالَ أَخْبَرَنَا هِشَامُ بْنُ عُرْوَةَ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، قَالَتْ أَمَرَ رَسُولُ اللَّهِ صلى الله عليه وسلم أَبَا بَكْرٍ أَنْ يُصَلِّيَ بِالنَّاسِ فِي مَرَضِهِ، فَكَانَ يُصَلِّي بِهِمْ‏.‏ قَالَ عُرْوَةُ فَوَجَدَ رَسُولُ اللَّهِ صلى الله عليه وسلم فِي نَفْسِهِ خِفَّةً، فَخَرَجَ فَإِذَا أَبُو بَكْرٍ يَؤُمُّ النَّاسَ، فَلَمَّا رَآهُ أَبُو بَكْرٍ اسْتَأْخَرَ، فَأَشَارَ إِلَيْهِ أَنْ كَمَا أَنْتَ، فَجَلَسَ رَسُولُ اللَّهِ صلى الله عليه وسلم حِذَاءَ أَبِي بَكْرٍ إِلَى جَنْبِهِ، فَكَانَ أَبُو بَكْرٍ يُصَلِّي بِصَلاَةِ رَسُولِ اللَّهِ صلى الله عليه وسلم وَالنَّاسُ يُصَلُّونَ بِصَلاَةِ أَبِي بَكْرٍ‏.‏