Muwatta Malik, Book 8, Hadith 308 (In-Book)

Yahya related to me from Malik from Hisham ibn Urwa from his father that the Messenger of Allah, may Allah bless him and grant him peace, came out during his illness, and approached and found Abu Bakr standing, leading the people in prayer. Abu Bakr began to go back, but the Messenger of Allah, may Allah bless him and grant him peace, indicated to him to stay where he was. The Messenger of Allah, may Allah bless him and grant him peace, sat by the side of Abu Bakr, and Abu Bakr prayed following the prayer of the Messenger of Allah, may Allah bless him and grant him peace, who was sitting, and the people prayed following the prayer of Abu Bakr.

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم خَرَجَ فِي مَرَضِهِ فَأَتَى فَوَجَدَ أَبَا بَكْرٍ وَهُوَ قَائِمٌ يُصَلِّي بِالنَّاسِ فَاسْتَأْخَرَ أَبُو بَكْرٍ فَأَشَارَ إِلَيْهِ رَسُولُ اللَّهِ صلى الله عليه وسلم أَنْ كَمَا أَنْتَ فَجَلَسَ رَسُولُ اللَّهِ صلى الله عليه وسلم إِلَى جَنْبِ أَبِي بَكْرٍ فَكَانَ أَبُو بَكْرٍ يُصَلِّي بِصَلاَةِ رَسُولِ اللَّهِ صلى الله عليه وسلم وَهُوَ جَالِسٌ وَكَانَ النَّاسُ يُصَلُّونَ بِصَلاَةِ أَبِي بَكْرٍ ‏.‏

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also referenced under: Book 8, Hadith 19 (USC-MSA)