Imam 'Ali (A.S.) said, describing those companions who are seen as among the earliest companions: "When I finally accepted the matter [of leadership], one group broke [their pledge]; the other deviated and others missed the truth as if they did not hear Allah's words when He said: "That is the abode of the hereafter that we have created for those who do not strive to exalt themselves in the earth nor to create mischief. The best outcome is [for] the pious ones". Nay, indeed, by Allah, they heard and perceived it's meaning but alas! the world seemed glittering in their eyes and it's embellishments seduced them"...(Nahj al-Balagha, p. 90).
And he (A.S.) also said about them: "They chose Satan as their master in their affairs, and he made them partners. He has laid eggs and hatched them in their bosoms. He creeps and crawls in their laps, he sees through their eyes and speaks through their tongues. He has led them to sins and adorned for them what is foul, like the action of one whom Satan has made a partner in his authority and speaks falsehood through his tongue (Nahj al-Balagha page 96).
He said regarding 'Amr b. al-'As, the famous companion: "How strange it is with the son of Nabigha .. he has uttered falsehood and sinned with his tongue. Is not the worst of speech, lies? When he speaks, he lies; when he promises, he breaks [it]; when he seeks a favour, he nags; and when he is asked for something, he is miserly. He betrays his pledge, and he ignores kinship..." (Nahj al-Balagha, page 200).
The Prophet of Allah said: "The signs of a hypocrite are three: When he speaks, he lies; when he promises he breaks [it]; when he is entrusted [with something], he betrays". All these vices, and even more than these were present in 'Amr b. al-'As.
He said, in praise of Abu Dharr al-Ghifari and in criticism of 'Uthman and those with him who had banished him to Rabdha, and exiled him till he died alone: "O Abu Dharr, You were angry for Allah's sake, so place your hopes in Him for whom you were angry. The people were afraid of you for their world, and you feared them for your religion. So leave in their hands that, due to which, they were afraid of you, and flee with that, due to which, you feared them. How badly they need what you have denied them and how little you need what they have denied you. Tomorrow you will know who has profited and you will know the envious ones. Were the skies and the earth a burden for a servant and were he to fear Allah, then Allah would remove his burden. So love nothing but the truth and hate nothing but lies. Had you accepted their world, they would have loved you, had you appropriated to yourself some part of it, they would have given you asylum" (Nahj al-Balagha, page 299).
Regarding al-Mughira b. al-Akhnas, who was also a prominent companion, he (A.S.) said: "O son of the accursed one! O tree which has neither root nor branch. By Allah, He will not assist whoever you help and whoever you raise will not stand straight. Go away from us. May Allah distance you from your purpose. Do what you like, and may His mercy be withheld from you if you remain alone" (Nahj al-Balagha, p. 306).
He (A.S.) said of Talha and al-Zubayr, the two famous companions who waged war against him after having sworn their oaths of allegiance to him, then they breached it: "By Allah, they did not find any evil in me, they did not do justice between me and them. They are demanding a right which they abandoned and blood which they spilled". This is a rebellious group which contains the near one (Zubayr), the scorpion's venom and doubts which cast veils. The matter is clear and falsehood has been shaken from it's foundation, and it's tongue has stopped uttering mischief.
You hurried to me shouting allegiance! allegiance! like she camels having delivered newly born young ones, leaping towards their young. I held back my hand but you pulled it towards yourself. I drew back my hand but you dragged it. O Allah, these two have severed all bonds of friendship and wronged me! They broke their oaths and instigated the people against me. My Lord, let what they plot against me fail. Unfasten what they have tied, and do not make strong what they have woven. Show them the evil of what they aimed and acted upon. Before the battle, I gave them a chance to correct their deed and treated them with respect but they belittled the blessing and refused the safety" (Nahj al-Balagha, p. 306).
In a letter to them, he said: "O two respected Shaykhs! Revert from your present position for the worst that can befall you now is shame. Later, both shame and hell fire will be combined [against you]. Peace" (Nahj al-Balagha, p. 626).
Regarding Marwan b. al-Hakam, who had been taken as captive at the battle of the Camel, then set free. He was amongst those who had given a pledge and then broke the pledge: "No need have I for his pledge for it is the palm of a Jew. If he swears with his hand, he will violate it after a short while. He will get power for so long as a dog licks it's nose, he is the father of four rams who will also rule. The people will face hard days through him and his sons" (Nahj al-Balagha, p. 176).
He said of those companions who journeyed with 'A'isha to Basra in the battle of the Camel, amongst them were Talha and Zubayr: "They came out dragging the wife of the Prophet (S.A.W.) just as a maid slave is dragged for sale. They took her to Basra where they put their women in their houses but exposed the wife of the Prophet (S.A.W.) to themselves and to others in the army in which there was not a single person who had not offered me his obedience and sworn to me allegiance willingly, without being forced. They approached my officers and treasurers of the public treasury and its other inhabitants. They killed some of them in prison and others by treachery. By Allah, even if they had killed willfully a single Muslim without any fault, it would have been lawful for me to kill the whole of this army because they were present in it but did not disagree with it nor prevented it by tongue or hand, not to say that they killed Muslims of a number equal to that with which had marched on them" (Nahj al-Balagha, page 370).
His words regarding 'A'isha and the companions who followed her at the battle of the Camel: "You were the soldiers of a woman and the followers of an animal. The animal snorted and you responded, and when it was killed you fled. Your character is low, your pledge is broken and your religion is hypocritical" (Nahj al-Balagha p. 98).
"As for so and so, she is gripped by feminine views while malice is boiling in her bosom like the furnace of a blacksmith. If she were called upon to deal with others as she is dealing with me she would not have done it. Even then she will be given the original respect, while her accounting [of her acts] is with Allah". (Nahj al-Balagha, p. 334).
As for the general Quraysh, who were certainly companions, he said about them: "As for the eviction of us from this position, although we were the highest as far as descent was concerned and the strongest in relationship with the Prophet of Allah (S.A.W.), it was a selfish act towards which the hearts of the people became greedy while some people did not care for it. The arbiter is Allah and to Him is the return on the day of Judgement. Leave this story of devastation about which there is hue and cry. Come and look at the son of Abu Sufyan. Time has made me laugh after weeping. No wonder, by Allah, what is this affair which surpasses all wonder and which has increased wrong doing? The people have tried to extinguish the light of Allah from His lamp and to close His fountain from it's sources. They mix epidemic producing water between me and themselves. If the trying hardships are removed from us, I would take them on the course of the truth, otherwise I do not feel sorry for them. 'Do not let your soul go out vainly, sighing after them. Surely, Allah knows what they are doing'" (Nahj al-Balagha, p. 348).
When he buried Fatima al-Zahra, leader of the women of paradise, he addressed the Prophet thus:"Your daughter will inform you of how the
umma joined together to oppress her. Ask her in detail and she will explain the situation. This has happened when you have recently left us and your remembrance has not disappeared" (Nahj-al Balagha, 460).
In a letter to Mu'awiya, 'Ali (A.S.) said:
"You are one whom the devil has taken complete possession of, he has secured his wishes in you and has taken complete control over you like the soul and blood. When were you, O Mu'awiya, the protector of the subjects and guardian of the affairs of the people? Without any forward step or conspicuous distinction? We seek Allah's protection against the befalling of previous misfortunes and I warn you lest you continue getting deceived by desires and your appearance be different from your inner self.
You have called me to war. Leave the people on one side, come out to me [for fighting] and spare both parties from fighting so that it may be known which of us has a rusted heart and covered eyes. I am Abu'l-Hasan, slayer of your father, your uncle and your brother, all in single combat on the day of Badr. That same sword is still with me and I meet my adversary with the same heart. I have not altered the religion nor put up any new Prophet. I am surely heading on that very path which you had willingly forsaken and which you had embraced by force (Nahj al-Balagha, 526).
As for what you say, that "We are of the progeny of 'Abd al-Manaf", so too are we. But Umayya was not like Hashim, nor Harb equal to 'Abd al-Muttalib, nor Abu Sufyan to Abu Talib nor one freed (at the conquest of Mecca) equal to a Muhajir, nor one of clean descent a match for him who has been adopted, nor the truthful one the same as one on falsehood, nor is a believer a match for a hypocrite. How bad are the successors who go on following the predecessors who have fallen in hell.
Besides that, we also have the distinction of Prophethood among us, by virtue of which we subdued the strong and raised up the down trodden. When Allah caused the Arabs to enter his religion in overwhelming numbers, and this umma accepted Islam, some did so willingly while others did so forcefully. You were among those who entered Islam due to greed or fear at a time when others had preceded and the first Muhajirs had taken away all the distinction (Nahj al-Balagha, page 533).
You have called us to follow the judgment of the Qur'an but you are not the people of the Qur'an. We did not accept your proposal but we respond to the Qur'anic injunctions, Peace" (Nahj al-Balagha, 595).
"And say: 'Truth has come and falsehood has vanished. Falsehood [is bound] to perish'".
source : http://www.islamicecenter.com/e-library/logic_islamic_rules/logic_islamic_rules_makarem_subhani_03.html