Hadithcore
Sahih al-Bukhari, 3669, 3670
sahih

'Aisha said (in another narration), ("When the Prophet (ﷺ) was on his death-bed) he looked up and said thrice, (Amongst) the Highest Companion (See Qur'an 4:69)' Aisha said, Allah benefited the people by their two speeches. 'Umar frightened the people some of whom were hypocrites whom Allah caused to abandon Islam because of 'Umar's speech. Then Abu Bakr led the people to True Guidance and acquainted them with the right path they were to follow so that they went out reciting:

-- "Muhammad is no more than an Messenger and indeed many Messengers have passed away before him.." (3:144)

وَقَالَ عَبْدُ اللَّهِ بْنُ سَالِمٍ عَنِ الزُّبَيْدِيِّ، قَالَ عَبْدُ الرَّحْمَنِ بْنُ الْقَاسِمِ أَخْبَرَنِي الْقَاسِمُ، أَنَّ عَائِشَةَ ـ رضى الله عنها ـ قَالَتْ شَخَصَ بَصَرُ النَّبِيِّ صلى الله عليه وسلم ثُمَّ قَالَ ‏

‏ فِي الرَّفِيقِ الأَعْلَى ‏

‏‏.‏ ثَلاَثًا، وَقَصَّ الْحَدِيثَ، قَالَتْ فَمَا كَانَتْ مِنْ خُطْبَتِهِمَا مِنْ خُطْبَةٍ إِلاَّ نَفَعَ اللَّهُ بِهَا، لَقَدْ خَوَّفَ عُمَرُ النَّاسَ وَإِنَّ فِيهِمْ لَنِفَاقًا، فَرَدَّهُمُ اللَّهُ بِذَلِكَ‏.‏ ثُمَّ لَقَدْ بَصَّرَ أَبُو بَكْرٍ النَّاسَ الْهُدَى وَعَرَّفَهُمُ الْحَقَّ الَّذِي عَلَيْهِمْ وَخَرَجُوا بِهِ يَتْلُونَ ‏{‏وَمَا مُحَمَّدٌ إِلاَّ رَسُولٌ قَدْ خَلَتْ مِنْ قَبْلِهِ الرُّسُلُ‏}‏ إِلَى ‏{‏الشَّاكِرِينَ‏}‏

References2 variants
In-Book Reference
Book 62, Hadith 20
USC-MSA web (English) reference
Vol. 5, Book 57, Hadith 19 (deprecated numbering scheme)