Volume 5, Book 57, Number 18: (Sahih Bukhari)
Narrated Abu Huraira: I heard Allah's Apostle saying, "Anybody who spends a pair of something in Allah's Cause will be called from all the gates of Paradise, "O Allah's slave! This is good.' He who is amongst those who pray will be called from the gate of the prayer (in Paradise) and he who is from the people of Jihad will be called from the gate of Jihad, and he who is from those' who give in charity (i.e. Zakat) will be called from the gate of charity, and he who is amongst those who observe fast will be called from the gate of fasting, the gate of Raiyan." Abu Bakr said, "He who is called from all those gates will need nothing," He added, "Will anyone be called from all those gates, O Allah's Apostle?" He said, "Yes, and I hope you will be among those, O Abu Bakr
Volume 5, Book 57, Number 20: (Sahih Bukhari)
Narrated Muhammad bin Al-Hanafiya: I asked my father ('Ali bin Abi Talib), "Who are the best people after Allah's Apostle ?" He said, "Abu Bakr." I asked, "Who then?" He said, "Then 'Umar. " I was afraid he would say "Uthman, so I said, "Then you?
..." He said, "I am only an ordinary person.
Volume 5, Book 57, Number 8: (Sahih Bukhari)
Narrated Ibn 'Abbas: The Prophet said, "If I were to take a Khalil, I would have taken Abu Bakr, but he is my brother and my companion (in Islam)."
“The first amongst men to enter paradise”
Book 40, Number 4635: (Sunnan Abu Dawud)
Narrated AbuHurayrah: The Prophet (peace_be_upon_him) said: Gabriel came and taking me by the hand showed the gate of Paradise by which my people will enter. AbuBakr then said: Apostle of Allah! I wish I had been with you so that I might have looked at it. The Apostle of Allah (peace_be_upon_him) then said: You, AbuBakr, will be the first of my people to enter Paradise.
“The Prophet (salallaho alaihi wasalam) already knew what will happen to his most eminent Sahaba”
Volume 5, Book 57, Number 24: (Sahih Bukhari)
Narrated Anas bin Malik: The Prophet once climbed the mountain of Uhud with Abu Bakr, 'Umar and 'Uthman. The mountain shook with them. The Prophet said (to the mountain), "Be firm, O Uhud! For on you there are no more than a Prophet, a Siddiq and two martyrs.
“The one to refer after demise of Prophet (salallaho alaihi wasalam) i.e. First one to be appointed as Khalifa”
Volume 5, Book 57, Number 11: (Sahih Bukhari)
Narrated Jubair bin Mutim: A woman came to the Prophet who ordered her to return to him again. She said, "What if I came and did not find you?" as if she wanted to say, "If I found you dead?" The Prophet said, "If you should not find me, go to Abu Bakr."