Narrated Abdullah ibn Zam'ah:

When the illness of the Messenger of Allah ﷺ became serious while I was with him among a group of people, Bilal called him for prayer. He said: Ask someone to lead the people in prayer. So Abdullah ibn Zam'ah went out and found that Umar was present among the people and AbuBakr was not there. I said: Umar, get up and lead the people in prayer. So he came forward and uttered "Allah is Most Great". When the Messenger of Allah ﷺ heard his voice, as Umar had a loud voice, he said: Where is AbuBakr? Allah does not allow that, and the Muslims too; Allah does not allow that, and the Muslims too. So he sent for AbuBakr. He came after Umar had led the people in that prayer. He then led the people in prayer.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ النُّفَيْلِيُّ، حَدَّثَنَا مُحَمَّدُ بْنُ سَلَمَةَ، عَنْ مُحَمَّدِ بْنِ إِسْحَاقَ، قَالَ حَدَّثَنِي الزُّهْرِيُّ، حَدَّثَنِي عَبْدُ الْمَلِكِ بْنُ أَبِي بَكْرِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ الْحَارِثِ بْنِ هِشَامٍ، عَنْ أَبِيهِ، عَنْ عَبْدِ اللَّهِ بْنِ زَمْعَةَ، قَالَ لَمَّا اسْتُعِزَّ بِرَسُولِ اللَّهِ ﷺ وَأَنَا عِنْدَهُ فِي نَفَرٍ مِنَ الْمُسْلِمِينَ دَعَاهُ بِلاَلٌ إِلَى الصَّلاَةِ فَقَالَ مُرُوا مَنْ يُصَلِّي لِلنَّاسِ . فَخَرَجَ عَبْدُ اللَّهِ بْنُ زَمَعَةَ فَإِذَا عُمَرُ فِي النَّاسِ وَكَانَ أَبُو بَكْرٍ غَائِبًا فَقُلْتُ يَا عُمَرُ قُمْ فَصَلِّ بِالنَّاسِ فَتَقَدَّمَ فَكَبَّرَ فَلَمَّا سَمِعَ رَسُولُ اللَّهِ ﷺ صَوْتَهُ وَكَانَ عُمَرُ رَجُلاً مُجْهِرًا قَالَ " فَأَيْنَ أَبُو بَكْرٍ يَأْبَى اللَّهُ ذَلِكَ وَالْمُسْلِمُونَ يَأْبَى اللَّهُ ذَلِكَ وَالْمُسْلِمُونَ " . فَبَعَثَ إِلَى أَبِي بَكْرٍ فَجَاءَ بَعْدَ أَنْ صَلَّى عُمَرُ تِلْكَ الصَّلاَةَ فَصَلَّى بِالنَّاسِ .