From Authentic sources
From "The Devils Deception", A translation of "Tablees Iblees" of Ibn al-Jawzee, Edited and translated by Dr. Abu Ameenah Bilal Philips Shi'ites
Suwaid ibn Ghafalah 1 reported that once he passed by a group of Shee`ah who were talking about Abu Bakr and `Umar in derogatory terms. Then he visited `Alee ibn Abee Talib and told him:
"O Ameer al-Mu`mineen, I passed by a group of your companions while they were referring to Abu Bakr and `Umar in derogatory terms. If it were not that they thought that you secretly felt as they openly said, they would not have dared to say it."
`Alee replied: "I seek refuge in Allaah! I seek refuge in Allaah from secretly feeling anything towards the two of them other than what the Prophet entrusted to me. May Allaah curse anyone who holds inside himself anything but goodness and gratitude towards both of them. (They were like) two brothers to Allaah`s Messenger , his two companions, his two assistants, may Allaah`s mercy be on both of them."
Then `Alee got up with tears in his eyes, holding on to my hand until he entered the masjid. Next he ascended the mimber and sat at its top holding on to his beard and looking at it until the people gathered. After having made a brief but eloquent speech, he added:
"What is wrong with those who make allegations about the two masters of Quraysh, the two fathers of the Muslims, allegations which I would never say, or want to hear others say; and for which I may be punished. By He who split the seed and created the soul, only a pious believer loves them, and only a wretched sinner hates them. Those two who accompanied Allaah`s Messenger , commanding all that is good and prohibiting all that is evil; who became angry with wrongdoers and punished them based on truth and honesty alone. In their rulings, they did not overstep the opinion`s of Allaah`s Messenger . In fact, their opinions always coincided with those of Allaah`s Messenger and the believers were pleased with both of them throughout their respective caliphates.
The Messenger of Allaah appointed Abu Bakr to lead the believers in their prayers for the last nine days of the Prophet`s life and he died without recalling him. The believers, subsequently, made him responsible for their affairs, and gave him their Zakaah. They willingly pledged allegiance to him and I am the first person from Banu `Abd al-Muttalib to confirm his leadership. He disliked leadership and wished that one of us would take his place. By Allaah, he was the best of those who remained after the Prophet ; the eldest, the kindest, and truly the most compassionate and pious. He was like angel Mikaaeel in his benevolence and Prophet Ibraaheem (AS) in his willingness to forgive and his dignified bearing. He took the path of the Prophet and passed away on that path (may Allaah have mercy on him).
After Abu Bakr , `Umar took command, and I was among those pleased with his appointment. He ruled according to the policy of Allaah`s Messenger and his companion, Abu Bakr , following their footsteps the way a young camel follows its mother. I swear by Allaah, he was kind and gentle with the weak, a champion of the cause of the oppressed and without any blame concerning Allaah`s religion. Allaah manifested examples of the truth through him and made the truth a part of him to such a degree that we used to think that an angel was speaking with his tongue. Allaah made his conversion a strengthening factor for Islaam, and placed in the hearts of the Hypocrites a fear of him and in the hearts of the believers love for him. Allaah`s Messenger compared him to Angel Jibreel in his harshness towards the enemies of Islaam. So who among you can be compared to the two of them. May Allaah`s mercy be on them, and may Allaah provide us with the ability to continue in their paths. Let whoever loves me, love them, for whoever does not love them has angered me, and I will have nothing to do with him. If I hear anymore derogatory talk about the two of them, I will punish the offenders severely. After today, whoever is brought before me will get the punishment of a slanderer. Verily, the best of this nation after its Prophet is Abu Bakr and `Umar . Then Allaah knows best who is the best. I am saying this asking Allaah`s forgiveness for both you and myself."
1) Suwaid ibn Ghafalah was among the major scholars of the Taabi`oon. He accepted Islaam during the lifetime of the Prophet but never met him. On the day that the Prophet was being buried in al-Madeenah, Suwaid came to the city for the first time. He later settled in Kufah and died at the age of 130 in the year 700 CE. All the major books of Ahaadeeth have ahaadeeth narrated by Him. Ibn Hajar, Taqreeb at-Tahtheeb, Vol. 1, p. 341.