Sahih al-Bukhari 3667, 3668
Narrated 'Aisha:
(the wife of the Prophet) Allah's Messenger (ﷺ) died while Abu Bakr was at a place called As-Sunah (Al-'Aliya) 'Umar stood up and said, "By Allah! Allah's Messenger (ﷺ) is not dead!" 'Umar (later on) said, "By Allah! Nothing occurred to my mind except that." He said, "Verily! Allah will resurrect him and he will cut the hands and legs of some men." Then Abu Bakr came and uncovered the face of Allah's Messenger (ﷺ), kissed him and said, "Let my mother and father be sacrificed for you, (O Allah's Messenger (ﷺ)), you are good in life and in death. By Allah in Whose Hands my life is, Allah will never make you taste death twice." Then he went out and said, "O oath-taker! Don't be hasty." When Abu Bakr spoke, 'Umar sat down. Abu Bakr praised and glorified Allah and said, No doubt! Whoever worshipped Muhammad, then Muhammad is dead, but whoever worshipped Allah, then Allah is Alive and shall never die." Then he recited Allah's Statement.:-- "(O Muhammad) Verily you will die, and they also will die." (39.30) He also recited:--  "Muhammad is no more than an Apostle; and indeed many Apostles have passed away, before him, If he dies Or is killed, will you then Turn back on your heels? And he who turns back On his heels, not the least Harm will he do to Allah And Allah will give reward to those Who are grateful." (3.144)  The people wept loudly, and the Ansar were assembled with Sad bin 'Ubada in the shed of Bani Saida. They said (to the emigrants). "There should be one 'Amir from us and one from you." Then Abu Bakr, Umar bin Al-Khattab and Abu 'baida bin Al-Jarrah went to them. 'Umar wanted to speak but Abu Bakr stopped him. 'Umar later on used to say, "By Allah, I intended only to say something that appealed to me and I was afraid that Abu Bakr would not speak so well. Then Abu Bakr spoke and his speech was very eloquent. He said in his statement, "We are the rulers and you (Ansars) are the ministers (i.e. advisers)," Hubab bin Al-Mundhir said, "No, by Allah we won't accept this. But there must be a ruler from us and a ruler from you." Abu Bakr said, "No, we will be the rulers and you will be the ministers, for they (i.e. Quarish) are the best family amongst the 'Arabs and of best origin. So you should elect either 'Umar or Abu 'Ubaida bin Al-Jarrah as your ruler." 'Umar said (to Abu Bakr), "No but we elect you, for you are our chief and the best amongst us and the most beloved of all of us to Allah's Messenger (ﷺ)." So 'Umar took Abu Bakr's hand and gave the pledge of allegiance and the people too gave the pledge of allegiance to Abu Bakr. Someone said, "You have killed Sad bin Ubada." 'Umar said, "Allah has killed him."
حَدَّثَنَا إِسْمَاعِيلُ بْنُ عَبْدِ اللَّهِ، حَدَّثَنَا سُلَيْمَانُ بْنُ بِلاَلٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ عُرْوَةَ بْنِ الزُّبَيْرِ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ زَوْجِ النَّبِيِّ صلى الله عليه وسلم أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم مَاتَ وَأَبُو بَكْرٍ بِالسُّنْحِ ـ قَالَ إِسْمَاعِيلُ يَعْنِي بِالْعَالِيَةِ ـ فَقَامَ عُمَرُ يَقُولُ وَاللَّهِ مَا مَاتَ رَسُولُ اللَّهِ صلى الله عليه وسلم‏.‏ قَالَتْ وَقَالَ عُمَرُ وَاللَّهِ مَا كَانَ يَقَعُ فِي نَفْسِي إِلاَّ ذَاكَ وَلَيَبْعَثَنَّهُ اللَّهُ فَلَيَقْطَعَنَّ أَيْدِيَ رِجَالٍ وَأَرْجُلَهُمْ‏.‏ فَجَاءَ أَبُو بَكْرٍ فَكَشَفَ عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم فَقَبَّلَهُ قَالَ بِأَبِي أَنْتَ وَأُمِّي طِبْتَ حَيًّا وَمَيِّتًا، وَالَّذِي نَفْسِي بِيَدِهِ لاَ يُذِيقُكَ اللَّهُ الْمَوْتَتَيْنِ أَبَدًا‏.‏ ثُمَّ خَرَجَ فَقَالَ أَيُّهَا الْحَالِفُ عَلَى رِسْلِكَ‏.‏ فَلَمَّا تَكَلَّمَ أَبُو بَكْرٍ جَلَسَ عُمَرُ‏.‏ فَحَمِدَ اللَّهَ أَبُو بَكْرٍ وَأَثْنَى عَلَيْهِ وَقَالَ أَلاَ مَنْ كَانَ يَعْبُدُ مُحَمَّدًا صلى الله عليه وسلم فَإِنَّ مُحَمَّدًا قَدْ مَاتَ، وَمَنْ كَانَ يَعْبُدُ اللَّهَ فَإِنَّ اللَّهَ حَىٌّ لاَ يَمُوتُ‏.‏ وَقَالَ ‏{‏إِنَّكَ مَيِّتٌ وَإِنَّهُمْ مَيِّتُونَ‏}‏ وَقَالَ ‏{‏وَمَا مُحَمَّدٌ إِلاَّ رَسُولٌ قَدْ خَلَتْ مِنْ قَبْلِهِ الرُّسُلُ أَفَإِنْ مَاتَ أَوْ قُتِلَ انْقَلَبْتُمْ عَلَى أَعْقَابِكُمْ وَمَنْ يَنْقَلِبْ عَلَى عَقِبَيْهِ فَلَنْ يَضُرَّ اللَّهَ شَيْئًا وَسَيَجْزِي اللَّهُ الشَّاكِرِينَ‏}‏ قَالَ فَنَشَجَ النَّاسُ يَبْكُونَ ـ قَالَ ـ وَاجْتَمَعَتِ الأَنْصَارُ إِلَى سَعْدِ بْنِ عُبَادَةَ فِي سَقِيفَةِ بَنِي سَاعِدَةَ فَقَالُوا مِنَّا أَمِيرٌ وَمِنْكُمْ أَمِيرٌ، فَذَهَبَ إِلَيْهِمْ أَبُو بَكْرٍ وَعُمَرُ بْنُ الْخَطَّابِ وَأَبُو عُبَيْدَةَ بْنُ الْجَرَّاحِ، فَذَهَبَ عُمَرُ يَتَكَلَّمُ فَأَسْكَتَهُ أَبُو بَكْرٍ، وَكَانَ عُمَرُ يَقُولُ وَاللَّهِ مَا أَرَدْتُ بِذَلِكَ إِلاَّ أَنِّي قَدْ هَيَّأْتُ كَلاَمًا قَدْ أَعْجَبَنِي خَشِيتُ أَنْ لاَ يَبْلُغَهُ أَبُو بَكْرٍ، ثُمَّ تَكَلَّمَ أَبُو بَكْرٍ فَتَكَلَّمَ أَبْلَغَ النَّاسِ فَقَالَ فِي كَلاَمِهِ نَحْنُ الأُمَرَاءُ وَأَنْتُمُ الْوُزَرَاءُ‏.‏ فَقَالَ حُبَابُ بْنُ الْمُنْذِرِ لاَ وَاللَّهِ لاَ نَفْعَلُ، مِنَّا أَمِيرٌ وَمِنْكُمْ أَمِيرٌ‏.‏ فَقَالَ أَبُو بَكْرٍ لاَ، وَلَكِنَّا الأُمَرَاءُ وَأَنْتُمُ الْوُزَرَاءُ هُمْ أَوْسَطُ الْعَرَبِ دَارًا، وَأَعْرَبُهُمْ أَحْسَابًا فَبَايِعُوا عُمَرَ أَوْ أَبَا عُبَيْدَةَ‏.‏ فَقَالَ عُمَرُ بَلْ نُبَايِعُكَ أَنْتَ، فَأَنْتَ سَيِّدُنَا وَخَيْرُنَا وَأَحَبُّنَا إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم‏.‏ فَأَخَذَ عُمَرُ بِيَدِهِ فَبَايَعَهُ، وَبَايَعَهُ النَّاسُ، فَقَالَ قَائِلٌ قَتَلْتُمْ سَعْدَ بْنَ عُبَادَةَ‏.‏ فَقَالَ عُمَرُ قَتَلَهُ اللَّهُ‏.‏