(21) باب اسْتِخْلاَفِ الإِمَامِ إِذَا عَرَضَ لَهُ عُذْرٌ مِنْ مَرَضٍ وَسَفَرٍ وَغَيْرِهِمَا مَنْ يُصَلِّي بِالنَّاسِ وَأَنَّ مَنْ صَلَّى خَلْفَ إِمَامٍ جَالِسٍ لِعَجْزِهِ عَنِ الْقِيَامِ لَزِمَهُ الْقِيَامُ إِذَا قَدَرَ عَلَيْهِ وَنَسْخِ الْقُعُودِ خَلْفَ الْقَاعِدِ فِي حَقِّ مَنْ قَدَرَ عَلَى الْقِيَامِ
'A'isha reported:
When the Messenger of Allah (ﷺ) came to my house, he said: Ask Abu Bakr to lead people in prayer. 'A'isha narrated: I said, Messenger of Allah, Abu Bakr is a man of tenderly feelings; as he recites the Qur'an, he cannot help shedding tears: so better command anyone else to lead the prayer. By Allah, there is nothing disturbing in it for me but the idea that the people may not takeevil omen with regard to one who is the first to occupy the place of the Messenger of Allah (ﷺ). I tried to dissuade him (the Holy Prophet) twice or thrice (from appointing my father as an Imam in prayer), but he ordered Abu Bakr to lead the people in prayer and said: You women are like those (who had) surrounded Yusuf.
Reference: Sahih Muslim 418 e
In-book reference: Book 4, Hadith 102
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 836