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كتاب الأذان
10  
Call to Prayers (Adhaan)
(46)
Chapter: The religious learned men are entitled to precedence in leading the Salat (prayer)
(46)
باب أَهْلُ الْعِلْمِ وَالْفَضْلِ أَحَقُّ بِالإِمَامَةِ
Sahih al-Bukhari 678

Narrated Abu Musa:

"The Prophet (ﷺ) became sick and when his disease became aggravated, he said, "Tell Abu Bakr to lead the prayer." `Aisha said, "He is a softhearted man and would not be able to lead the prayer in your place." The Prophet (ﷺ) said again, "Tell Abu Bakr to lead the people in prayer." She repeated the same reply but he said, "Tell Abu Bakr to lead the people in prayer. You are the companions of Joseph." So the messenger went to Abu Bakr (with that order) and he led the people in prayer in the lifetime of the Prophet.

حَدَّثَنَا إِسْحَاقُ بْنُ نَصْرٍ، قَالَ حَدَّثَنَا حُسَيْنٌ، عَنْ زَائِدَةَ، عَنْ عَبْدِ الْمَلِكِ بْنِ عُمَيْرٍ، قَالَ حَدَّثَنِي أَبُو بُرْدَةَ، عَنْ أَبِي مُوسَى، قَالَ مَرِضَ النَّبِيُّ صلى الله عليه وسلم فَاشْتَدَّ مَرَضُهُ فَقَالَ ‏"‏ مُرُوا أَبَا بَكْرٍ فَلْيُصَلِّ بِالنَّاسِ ‏"‏‏.‏ قَالَتْ عَائِشَةُ إِنَّهُ رَجُلٌ رَقِيقٌ، إِذَا قَامَ مَقَامَكَ لَمْ يَسْتَطِعْ أَنْ يُصَلِّيَ بِالنَّاسِ‏.‏ قَالَ ‏"‏ مُرُوا أَبَا بَكْرٍ فَلْيُصَلِّ بِالنَّاسِ ‏"‏ فَعَادَتْ فَقَالَ ‏"‏ مُرِي أَبَا بَكْرٍ فَلْيُصَلِّ بِالنَّاسِ، فَإِنَّكُنَّ صَوَاحِبُ يُوسُفَ ‏"‏‏.‏ فَأَتَاهُ الرَّسُولُ فَصَلَّى بِالنَّاسِ فِي حَيَاةِ النَّبِيِّ صلى الله عليه وسلم‏.‏
Reference : Sahih al-Bukhari 678
In-book reference : Book 10, Hadith 72
USC-MSA web (English) reference : Vol. 1, Book 11, Hadith 646
  (deprecated numbering scheme)