Once, there was an argument between Abu Bakr and Umar Farooq, and Abu Bakr's comments were somewhat impolite. It was very unusual of him and he realized it a little later. Repentant, he went to apologize to Umar Farooq, who refused to accept the apology. Disappointed, Abu Bakr then went to the Prophet (saw) and submitted the whole story to him. Addressing Abu Bakr, the Prophet (saw) said three times: “May Allah forgive you.” Realizing what had happened, Umar Farooq rushed to see Abu Bakr at his home, but he wasn’t there. Umar then went to see the Prophet (saw). Seeing Umar, the Prophet (saw)’s face mirrored his inner displeasure and his eyes turned red. Suspecting Prophet (saw)’s displeasure may jeopardize Umar, Abu Bakr sat down meekly on his knees and in all humility submitted: “Ya Rasul Allah, it is but me, who had done wrong.” Addressing Umar, Prophet (saw) said: “Verily Allah (swt) sent me as a Messenger towards you, and you told me that I am a liar, but Abu Bakr affirmed and said: “You said the truth.” And Abu Bakr supported me with his heart, soul and resources. Wouldn’t you forgive my companion even for that reason?” Prophet (saw) repeated this last sentence twice. No one ever hurt the feelings of Abu Bakr as-Siddique after this incident.
Once Prophet (saw) was in the company of his companions, he (saw) inquired: “Who among you is fasting today?” Abu Bakr said: “I am fasting today Ya Rasul Allah.”
The Prophet asked again: “Who from among you participated in the funeral today and followed the bier?” Abu Bakr replied: “I did that, Ya Rasul Allah.”
The Prophet (saw) asked the third time: “Who fed the hungry from among you today?” Abu Bakr submitted: “Ya Rasul Allah, I did.”
The Prophet (saw) lastly asked: “Who from among you visited a sick person today?” Abu Bakr replied: “I did, Ya Rasul Allah.”
The Prophet (saw) said: “The one who has all these four attributes in him will surely enter Paradise.”
... Sahih Muslim