The book Saheeh Bukhari, compiled by Abu Abdillah Muhammad Ibn Ismail, later known as Imam Bukhari, is regarded as an important segment of the six so called authentic books (Sehaah-e-Sittah) of the Ahle Sunnah. After the Holy Quran, these six books are of utmost importance to the Sunnis when compared to other books. All the contents of these books are considered to be authentic and reliable and hence the term Saheeh.
Bukhari has quoted the second caliph Umar Ibn Khattab extensively on what transpired at the Saqifah of Bani Saa’edah:
Says Umar: Following the demise of the Holy Prophet (s.a.w.a.), news reached us that the Ansaar (Immigrants) had assembled at the Saqifah-i-Bani Saa’edah. I told Abu Bakr, ‘Let us go there so that we join our Ansaar brethren.’
Abu Bakr obliged and we reached Saqifah together. Ali, Zubair and their companions were not with us. At Saqifah, we observed that a group of Ansaar had brought someone with them who was completely covered. It was Sa’d ibn Ubaadah running a very high temperature. We sat besides them. A man from the Ansaar stood up and as had been decided, after praising Allah began to speak, ‘We are the friends and lovers of Allah. We are the soldiers and the strength of Islam. But you, O Muhaajireen, are few in number and …’
I (Umar) thought of replying but Abu Bakr pulled my sleeves and quietened me. He then himself stood up, and God is witness, said what I wanted to and he said it better than me.
Abu Bakr said, ‘O company of Ansaar! You are surely the recipient of the attributes which you have described and you have achieved them. But, Caliphate and government is only the right of the Quraish because they are renowned for their nobility and lineage, manners and conduct throughout the Arabian Peninsula and enjoy an undisputed position. It is only for your betterment that I do this, I present before you two people so that you may choose whomsoever you wish for the Caliphate. Saying this, Abu Bakr caught hold of my hand and that of Abu Ubaidah and presented us before the crowd. I disliked the last suggestion. While another Ansaar stood up and commented:
اَنَا جَذِيْلُهَا الْمَحْكُ وَ عَذِيْقُهَا الْمُوْجَبُ-
I am among you (O Ansaar) like a stick with which camels are driven or that tree which provides shade. If it is so, O Muhajireen! Then appoint a ruler amongst you and we will appoint one from amongst us. A great commotion erupted at this statement. We witnessed great opposition and rivalry. I took advantage of this commotion and said to Abu Bakr, ‘Extend your hand so that I may pay allegiance to you.’ Abu Bakr complied and I paid allegiance to him. Having done this, we gathered near Sa’d Bin Ubadah…. After this entire episode, if somebody pays allegiance to the Caliphate of any other caliph without the consultation of the Muslims, adhere neither to the follower nor the allegiance taker, for both are liable for capital punishment.
Saheeh Bukhari, Kitabul Hudud, Baabul Rajmul Hablaa, 4/ 119-120
Seerae Ibne Hisham, 4/ 336-338 Kanz al-Ummaal, 3/ 139- Hadith 2326