Sahih al-Bukhari 3667, 3668

It is related from 'A'isha, the wife of the Prophet, that the Messenger of Allah, may Allah bless him and grant him peace, died while Abu Bakr was at as-Sunh. (Isma'il says that it means at al-'Aliyya). 'Umar stood up saying, 'By Allah, the Messenger of Allah, may Allah bless him and grant him peace, has not died!'" She said, ''Umar said [later], 'By Allah, nothing occurred to me but that." [He said], 'Allah will raise him and he will cut off the hands and feets of some men!' Abu Bakr came and uncovered the Messenger of Allah, may Allah bless him and grant him peace, and kissed him. He said, 'By my mother and my father, you were good both alive and dead. By the One who has no soul in His hand, Allah will not ever make you taste two deaths. ' Then he went out and said, 'O oath-taker, take it easy. When Abu Bakr spoke, 'Umar sat down. He praised Allah and glorified Him and said, 'Whoever worshipped Muhammad, Muhammad is dead. Whoever worshipped Allah, Allah is alive and does not die.' He said, 'You will die and they too will die.' (39:30) He said, 'Muhammad is only a Messenger and he has been preceded by other Messengers. If he was to die or be killed, would you turn on your heels? Those who turn on their heels do not harm Allah in any way. Allah will recompense the thankful.' (3:144) The people sobbed." He said, "The Ansar gathered around Sa'd ibn 'Ubada in the Saqifa of the Banu Sa'ida. They said, 'There should be an amir from us and an amir from you.' Abu Bakr, 'Umar ibn al-Khattab, and Abu 'Ubayda ibn al-Jarrah went to them. 'Umar started to speak and Abu Bakr made him be quiet. 'Umar used to say, 'By Allah, I only meant by that some words which I had prepared which I liked. I was afraid that Abu Bakr would not be eloquent. Then Abu Bakr spoke and he spoke in the most eloquent fashion. He said in his words, "We are the amirs and you are the wazirs."' Hubab ibn al-Mundhir said, 'No, by Allah, we will not do it! An amir from us and an amir from you.' Abu Bakr said, 'No, but we are the amirs and you are the wazirs, for they (i.e. Quraysh) are the noblest house of the Arabs and the best in lineage. So give allegiance to 'Umar or Abu 'Ubadya ibn al-Jarrah.' So 'Umar said, 'Rather we will give allegiance to you! You are our master and the best of us and the one of us most beloved to the Messenger of Allah, may Allah bless him and grant him peace, and 'Umar took his hand and gave him allegiance, and the people gave him allegiance. Someone said, 'You have killed Sa'd.' 'Umar replied, 'Allah has killed him.'" It is related that 'A'isha said, "The eyes of the Prophet, may Allah bless him and grant him peace, became fixed and then he said three times, 'Among the highest Companion,'" He [al-Qasim] related the hadith. She said, "There was nothing in what both of them said by which Allah did not benefit people. 'Umar frightened the people, some of whom were hypocrites and then Allah caused them to apostasise because of that. Then Abu Bakr showed the people guidance and acquainted them with the truth which they were following. They went out reciting, 'Muhammad is only a Messenger and he has been preceded by other Messengers. If he was to die or be killed, would you turn on your heels? Those who turn on their heels do not harm Allah in any way. Allah will recompense the thankful.'"