Narrated `Abdullah bin `Abbas: `Ali bin Abu Talib came out of the house of the Prophet during his fatal ailment. The people asked (`Ali), "O Abu Hasan! How is the health of Allah's Apostle this morning?" `Ali said, "This morning he is better, with the grace of Allah." Al-`Abbas held `Ali by the hand and said, "Don't you see him (about to die)? By Allah, within three days you will be the slave of the stick (i.e., under the command of another ruler). By Allah, I think that Allah's Apostle will die from his present ailment, for I know the signs of death on the faces of the offspring of `Abdul Muttalib. So let us go to Allah's Apostle to ask him who will take over the Caliphate. If the authority is given to us, we will know it, and if it is given to somebody else we will request him to recommend us to him. " `Ali said, "By Allah! If we ask Allah's Apostle for the rulership and he refuses, then the people will never give it to us. Besides, I will never ask Allah's Apostle for it." (See Hadith No 728, Vol 5) Sahih Bukhari (6339)   
Narrated `Aisha: Fatima the daughter of the Prophet sent someone to Abu Bakr (when he was a caliph), asking for her inheritance of what Allah's Apostle had left of the property bestowed on him by Allah from the Fai (i.e. booty gained without fighting) in Medina, and Fadak, and what remained of the Khumus of the Khaibar booty. On that, Abu Bakr said, "Allah's Apostle said, "Our property is not inherited. Whatever we leave, is Sadaqa, but the family of (the Prophet) Muhammad can eat of this property.' By Allah, I will not make any change in the state of the Sadaqa of Allah's Apostle and will leave it as it was during the lifetime of Allah's Apostle, and will dispose of it as Allah's Apostle used to do." So Abu Bakr refused to give anything of that to Fatima. So she became angry with Abu Bakr and kept away from him, and did not task to him till she died. She remained alive for six months after the death of the Prophet. When she died, her husband `Ali, buried her at night without informing Abu Bakr and he said the funeral prayer by himself. When Fatima was alive, the people used to respect `Ali much, but after her death, `Ali noticed a change in the people's attitude towards him. So `Ali sought reconciliation with Abu Bakr and gave him an oath of allegiance. `Ali had not given the oath of allegiance during those months (i.e. the period between the Prophet's death and Fatima's death). `Ali sent someone to Abu Bakr saying, "Come to us, but let nobody come with you," as he disliked that `Umar should come, `Umar said (to Abu Bakr), "No, by Allah, you shall not enter upon them alone " Abu Bakr said, "What do you think they will do to me? By Allah, I will go to them' So Abu Bakr entered upon them, and then `Ali uttered Tashah-hud and said (to Abu Bakr), "We know well your superiority and what Allah has given you, and we are not jealous of the good what Allah has bestowed upon you, but you did not consult us in the question of the rule and we thought that we have got a right in it because of our near relationship to Allah's Apostle ." Thereupon Abu Bakr's eyes flowed with tears. And when Abu Bakr spoke, he said, "By Him in Whose Hand my soul is to keep good relations with the relatives of Allah's Apostle is dearer to me than to keep good relations with my own relatives. But as for the trouble which arose between me and you about his property, I will do my best to spend it according to what is good, and will not leave any rule or regulation which I saw Allah's Apostle following, in disposing of it, but I will follow." On that `Ali said to Abu Bakr, "I promise to give you the oath of allegiance in this after noon." So when Abu Bakr had offered the Zuhr prayer, he ascended the pulpit and uttered the Tashah-hud and then mentioned the story of `Ali and his failure to give the oath of allegiance, and excused him, accepting what excuses he had offered; Then `Ali (got up) and praying (to Allah) for forgiveness, he uttered Tashah-hud, praised Abu Bakr's right, and said, that he had not done what he had done because of jealousy of Abu Bakr or as a protest of that Allah had favored him with. `Ali added, "But we used to consider that we too had some right in this affair (of rulership) and that he (i.e. Abu Bakr) did not consult us in this matter, and therefore caused us to feel sorry." On that all the Muslims became happy and said, "You have done the right thing." The Muslims then became friendly with `Ali as he returned to what the people had done (i.e. giving the oath of allegiance to Abu Bakr). Sahih Bukhari (4287)   
Narrated Ibn `Abbas: I used to teach (the Qur'an to) some people of the Muhajirln (emigrants), among whom there was `Abdur Rahman bin `Auf. While I was in his house at Mina, and he was with `Umar bin Al-Khattab during `Umar's last Hajj, `Abdur-Rahman came to me and said, "Would that you had seen the man who came today to the Chief of the Believers (`Umar), saying, 'O Chief of the Believers! What do you think about so-and-so who says, 'If `Umar should die, I will give the pledge of allegiance to such-andsuch person, as by Allah, the pledge of allegiance to Abu Bakr was nothing but a prompt sudden action which got established afterwards.' `Umar became angry and then said, 'Allah willing, I will stand before the people tonight and warn them against those people who want to deprive the others of their rights (the question of rulership). `Abdur-Rahman said, "I said, 'O Chief of the believers! Do not do that, for the season of Hajj gathers the riff-raff and the rubble, and it will be they who will gather around you when you stand to address the people. And I am afraid that you will get up and say something, and some people will spread your statement and may not say what you have actually said and may not understand its meaning, and may interpret it incorrectly, so you should wait till you reach Medina, as it is the place of emigration and the place of Prophet's Traditions, and there you can come in touch with the learned and noble people, and tell them your ideas with confidence; and the learned people will understand your statement and put it in its proper place.' On that, `Umar said, 'By Allah! Allah willing, I will do this in the first speech I will deliver before the people in Medina." Ibn `Abbas added: We reached Medina by the end of the month of Dhul-Hijja, and when it was Friday, we went quickly (to the mosque) as soon as the sun had declined, and I saw Sa`id bin Zaid bin `Amr bin Nufail sitting at the corner of the pulpit, and I too sat close to him so that my knee was touching his knee, and after a short while `Umar bin Al-Khattab came out, and when I saw him coming towards us, I said to Sa`id bin Zaid bin `Amr bin Nufail "Today `Umar will say such a thing as he has never said since he was chosen as Caliph." Sa`id denied my statement with astonishment and said, "What thing do you expect `Umar to say the like of which he has never said before?" In the meantime, `Umar sat on the pulpit and when the callmakers for the prayer had finished their call, `Umar stood up, and having glorified and praised Allah as He deserved, he said, "Now then, I am going to tell you something which (Allah) has written for me to say. I do not know; perhaps it portends my death, so whoever understands and remembers it, must narrate it to the others wherever his mount takes him, but if somebody is afraid that he does not understand it, then it is unlawful for him to tell lies about me. Allah sent Muhammad with the Truth and revealed the Holy Book to him, and among what Allah revealed, was the Verse of the Rajam (the stoning of married person (male & female) who commits illegal sexual intercourse, and we did recite this Verse and understood and memorized it. Allah's Apostle did carry out the punishment of stoning and so did we after him. I am afraid that after a long time has passed, somebody will say, 'By Allah, we do not find the Verse of the Rajam in Allah's Book,' and thus they will go astray by leaving an obligation which Allah has revealed. And the punishment of the Rajam is to be inflicted to any married person (male & female), who commits illegal sexual intercourse, if the required evidence is available or there is conception or confession. And then we used to recite among the Verses in Allah's Book: 'O people! Do not claim to be the offspring of other than your fathers, as it is disbelief (unthankfulness) on your part that you claim to be the offspring of other than your real father.' Then Allah's Apostle said, 'Do not praise me excessively as Jesus, son of Marry was praised, but call me Allah's Slave and His Apostles.' (O people!) I have been informed that a speaker amongst you says, 'By Allah, if `Umar should die, I will give the pledge of allegiance to such-and-such person.' One should not deceive oneself by saying that the pledge of allegiance given to Abu Bakr was given suddenly and it was successful. No doubt, it was like that, but Allah saved (the people) from its evil, and there is none among you who has the qualities of Abu Bakr. Remember that whoever gives the pledge of allegiance to anybody among you without consulting the other Muslims, neither that person, nor the person to whom the pledge of allegiance was given, are to be supported, lest they both should be killed. And no doubt after the death of the Prophet we were informed that the Ansar disagreed with us and gathered in the shed of Bani Sa`da. `Ali and Zubair and whoever was with them, opposed us, while the emigrants gathered with Abu Bakr. I said to Abu Bakr, 'Let's go to these Ansari brothers of ours.' So we set out seeking them, and when we approached them, two pious men of theirs met us and informed us of the final decision of the Ansar, and said, 'O group of Muhajirin (emigrants) ! Where are you going?' We replied, 'We are going to these Ansari brothers of ours.' They said to us, 'You shouldn't go near them. Carry out whatever we have already decided.' I said, 'By Allah, we will go to them.' And so we proceeded until we reached them at the shed of Bani Sa`da. Behold! There was a man sitting amongst them and wrapped in something. I asked, 'Who is that man?' They said, 'He is Sa`d bin 'Ubada.' I asked, 'What is wrong with him?' They said, 'He is sick.' After we sat for a while, the Ansar's speaker said, 'None has the right to be worshipped but Allah,' and praising Allah as He deserved, he added, 'To proceed, we are Allah's Ansar (helpers) and the majority of the Muslim army, while you, the emigrants, are a small group and some people among you came with the intention of preventing us from practicing this matter (of caliphate) and depriving us of it.' When the speaker had finished, I intended to speak as I had prepared a speech which I liked and which I wanted to deliver in the presence of Abu Bakr, and I used to avoid provoking him. So, when I wanted to speak, Abu Bakr said, 'Wait a while.' I disliked to make him angry. So Abu Bakr himself gave a speech, and he was wiser and more patient than I. By Allah, he never missed a sentence that I liked in my own prepared speech, but he said the like of it or better than it spontaneously. After a pause he said, 'O Ansar! You deserve all (the qualities that you have attributed to yourselves, but this question (of Caliphate) is only for the Quraish as they are the best of the Arabs as regards descent and home, and I am pleased to suggest that you choose either of these two men, so take the oath of allegiance to either of them as you wish. And then Abu Bakr held my hand and Abu Ubada bin `Abdullah's hand who was sitting amongst us. I hated nothing of what he had said except that proposal, for by Allah, I would rather have my neck chopped off as expiator for a sin than become the ruler of a nation, one of whose members is Abu Bakr, unless at the time of my death my own-self suggests something I don't feel at present.' And then one of the Ansar said, 'I am the pillar on which the camel with a skin disease (eczema) rubs itself to satisfy the itching (i.e., I am a noble), and I am as a high class palm tree! O Quraish. There should be one ruler from us and one from you.' Then there was a hue and cry among the gathering and their voices rose so that I was afraid there might be great disagreement, so I said, 'O Abu Bakr! Hold your hand out.' He held his hand out and I pledged allegiance to him, and then all the emigrants gave the Pledge of allegiance and so did the Ansar afterwards. And so we became victorious over Sa`d bin Ubada (whom Al-Ansar wanted to make a ruler). One of the Ansar said, 'You have killed Sa`d bin Ubada.' I replied, 'Allah has killed Sa`d bin Ubada.' `Umar added, "By Allah, apart from the great tragedy that had happened to us (i.e. the death of the Prophet), there was no greater problem than the allegiance pledged to Abu Bakr because we were afraid that if we left the people, they might give the Pledge of allegiance after us to one of their men, in which case we would have given them our consent for something against our real wish, or would have opposed them and caused great trouble. So if any person gives the Pledge of allegiance to somebody (to become a Caliph) without consulting the other Muslims, then the one he has selected should not be granted allegiance, lest both of them should be killed." Sahih Bukhari (6918)   
Narrated `Amr bin Maimun: I saw `Umar bin Al-Khattab a few days before he was stabbed in Medina. He was standing with Hudhaifa bin Al-Yaman and `Uthman bin Hunaif to whom he said, "What have you done? Do you think that you have imposed more taxation on the land (of As-Swad i.e. 'Iraq) than it can bear?" They replied, "We have imposed on it what it can bear because of its great yield." `Umar again said, "Check whether you have imposed on the land what it can not bear." They said, "No, (we haven't)." `Umar added, "If Allah should keep me alive I will let the widows of Iraq need no men to support them after me." But only four days had elapsed when he was stabbed (to death ). The day he was stabbed, I was standing and there was nobody between me and him (i.e. `Umar) except `Abdullah bin `Abbas. Whenever `Umar passed between the two rows, he would say, "Stand in straight lines." When he saw no defect (in the rows), he would go forward and start the prayer with Takbir. He would recite Surat Yusuf or An-Nahl or the like in the first rak`a so that the people may have the time to Join the prayer. As soon as he said Takbir, I heard him saying, "The dog has killed or eaten me," at the time he (i.e. the murderer) stabbed him. A non-Arab infidel proceeded on carrying a double-edged knife and stabbing all the persons he passed by on the right and left (till) he stabbed thirteen persons out of whom seven died. When one of the Muslims saw that, he threw a cloak on him. Realizing that he had been captured, the non-Arab infidel killed himself, `Umar held the hand of `Abdur-Rahman bin `Auf and let him lead the prayer. Those who were standing by the side of `Umar saw what I saw, but the people who were in the other parts of the Mosque did not see anything, but they lost the voice of `Umar and they were saying, "Subhan Allah! Subhan Allah! (i.e. Glorified be Allah)." `Abdur-Rahman bin `Auf led the people a short prayer. When they finished the prayer, `Umar said, "O Ibn `Abbas! Find out who attacked me." Ibn `Abbas kept on looking here and there for a short time and came to say. "The slave of Al Mughira." On that `Umar said, "The craftsman?" Ibn `Abbas said, "Yes." `Umar said, "May Allah curse him. I did not treat him unjustly. All the Praises are for Allah Who has not caused me to die at the hand of a man who claims himself to be a Muslim. No doubt, you and your father (Abbas) used to love to have more non-Arab infidels in Medina." Al-Abbas had the greatest number of slaves. Ibn `Abbas said to `Umar. "If you wish, we will do." He meant, "If you wish we will kill them." `Umar said, "You are mistaken (for you can't kill them) after they have spoken your language, prayed towards your Qibla, and performed Hajj like yours." Then `Umar was carried to his house, and we went along with him, and the people were as if they had never suffered a calamity before. Some said, "Do not worry (he will be Alright soon)." Some said, "We are afraid (that he will die)." Then an infusion of dates was brought to him and he drank it but it came out (of the wound) of his belly. Then milk was brought to him and he drank it, and it also came out of his belly. The people realized that he would die. We went to him, and the people came, praising him. A young man came saying, "O chief of the believers! Receive the glad tidings from Allah to you due to your company with Allah's Apostle and your superiority in Islam which you know. Then you became the ruler (i.e. Caliph) and you ruled with justice and finally you have been martyred." `Umar said, "I wish that all these privileges will counterbalance (my shortcomings) so that I will neither lose nor gain anything." When the young man turned back to leave, his clothes seemed to be touching the ground. `Umar said, "Call the young man back to me." (When he came back) `Umar said, "O son of my brother! Lift your clothes, for this will keep your clothes clean and save you from the Punishment of your Lord." `Umar further said, "O `Abdullah bin `Umar! See how much I am in debt to others." When the debt was checked, it amounted to approximately eighty-six thousand. `Umar said, "If the property of `Umar's family covers the debt, then pay the debt thereof; otherwise request it from Bani `Adi bin Ka`b, and if that too is not sufficient, ask for it from Quraish tribe, and do not ask for it from any one else, and pay this debt on my behalf." `Umar then said (to `Abdullah), "Go to `Aisha (the mother of the believers) and say: "`Umar is paying his salutation to you. But don't say: 'The chief of the believers,' because today I am not the chief of the believers. And say: "`Umar bin Al-Khattab asks the permission to be buried with his two companions (i.e. the Prophet, and Abu Bakr)." `Abdullah greeted `Aisha and asked for the permission for entering, and then entered to her and found her sitting and weeping. He said to her, "`Umar bin Al-Khattab is paying his salutations to you, and asks the permission to be buried with his two companions." She said, "I had the idea of having this place for myself, but today I prefer `Umar to myself." When he returned it was said (to `Umar), "`Abdullah bin `Umar has come." `Umar said, "Make me sit up." Somebody supported him against his body and `Umar asked (`Abdullah), "What news do you have?" He said, "O chief of the believers! It is as you wish. She has given the permission." `Umar said, "Praise be to Allah, there was nothing more important to me than this. So when I die, take me, and greet `Aisha and say: "`Umar bin Al-Khattab asks the permission (to be buried with the Prophet ), and if she gives the permission, bury me there, and if she refuses, then take me to the grave-yard of the Muslims." Then Hafsa (the mother of the believers) came with many other women walking with her. When we saw her, we went away. She went in (to `Umar) and wept there for sometime. When the men asked for permission to enter, she went into another place, and we heard her weeping inside. The people said (to `Umar), "O chief of the believers! Appoint a successor." `Umar said, "I do not find anyone more suitable for the job than the following persons or group whom Allah's Apostle had been pleased with before he died." Then `Umar mentioned `Ali, `Uthman, AzZubair, Talha, Sa`d and `Abdur-Rahman (bin `Auf) and said, "Abdullah bin `Umar will be a witness to you, but he will have no share in the rule. His being a witness will compensate him for not sharing the right of ruling. If Sa`d becomes the ruler, it will be alright: otherwise, whoever becomes the ruler should seek his help, as I have not dismissed him because of disability or dishonesty." `Umar added, "I recommend that my successor takes care of the early emigrants; to know their rights and protect their honor and sacred things. I also recommend that he be kind to the Ansar who had lived in Medina before the emigrants and Belief had entered their hearts before them. I recommend that the (ruler) should accept the good of the righteous among them and excuse their wrong-doers, and I recommend that he should do good to all the people of the towns (Al-Ansar), as they are the protectors of Islam and the source of wealth and the source of annoyance to the enemy. I also recommend that nothing be taken from them except from their surplus with their consent. I also recommend that he do good to the 'Arab bedouin, as they are the origin of the 'Arabs and the material of Islam. He should take from what is inferior, amongst their properties and distribute that to the poor amongst them. I also recommend him concerning Allah's and His Apostle's protectees (i.e. Dhimmis) to fulfill their contracts and to fight for them and not to overburden them with what is beyond their ability." So when `Umar expired, we carried him out and set out walking. `Abdullah bin `Umar greeted (`Aisha) and said, "`Umar bin Al-Khattab asks for the permission." `Aisha said, "Bring him in." He was brought in and buried beside his two companions. When he was buried, the group (recommended by `Umar) held a meeting. Then `Abdur-Rahman said, " Reduce the candidates for rulership to three of you." Az-Zubair said, "I give up my right to `Ali." Talha said, "I give up my right to `Uthman," Sa`d, 'I give up my right to `Abdur-Rahman bin `Auf." `Abdur-Rahman then said (to `Uthman and `Ali), "Now which of you is willing to give up his right of candidacy to that he may choose the better of the (remaining) two, bearing in mind that Allah and Islam will be his witnesses." So both the sheiks (i.e. `Uthman and `Ali) kept silent. `Abdur-Rahman said, "Will you both leave this matter to me, and I take Allah as my Witness that I will not choose but the better of you?" They said, "Yes." So `Abdur-Rahman took the hand of one of them (i.e. `Ali) and said, "You are related to Allah's Apostle and one of the earliest Muslims as you know well. So I ask you by Allah to promise that if I select you as a ruler you will do justice, and if I select `Uthman as a ruler you will listen to him and obey him." Then he took the other (i.e. `Uthman) aside and said the same to him. When `Abdur-Rahman secured (their agreement to) this covenant, he said, "O `Uthman! Raise your hand." So he (i.e. `Abdur-Rahman) gave him (i.e. `Uthman) the solemn pledge, and then `Ali gave him the pledge of allegiance and then all the (Medina) people gave him the pledge of allegiance. Sahih Bukhari (3747)