Hadith 1:

الحسين بن محمد الاشعري، عن معلى بن محمد، عن الوشاء، عن أبان بن عثمان، عن عبد الرحمن بن أبي عبد الله قال: قلت لابي عبد الله (عليه السلام): إن الله عز وجل من علينا بأن عرفنا توحيده، ثم من علينا بأن أقررنا بمحمد (صلى الله عليه وآله) بالرسالة ثم اختصنا بحبكم أهل البيت نتولاكم ونتبرأ من عدوكم وإنما نريد بذلك خلاص أنفسنا من النار، قال: ورققت فبكيت، فقال أبو عبد الله (عليه السلام): سلني فوالله لا تسألني عن شئ إلا أخبرتك به، قال: فقال له عبد الملك بن أعين: ما سمعته قالها لمخلوق قبلك، قال: قلت: خبرني عن الرجلين؟ قال: ظلمانا حقنا في كتاب الله عز وجل ومنعا فاطمة صلوات الله عليها ميراثها من أبيها وجرى ظلمهما إلى اليوم، قال - وأشار إلى خلفه - ونبذا كتاب الله وراء ظهورهما

Narrated al-Husain bin Mohammad al-Ashari, from Mualla bin Mohammad, from al-Washa, from Aban bin Usman, from Abd al-Rahman bin Abi Abdillah who said,

I said to Abi Abdillah Imam Sadiq (as), "Allah blessed us with the recognition of His monotheism (Tawheed), then He blessed us with the belief in Muhammad's (saww) message, then He distinguished us with Your love the Ahl al-Bayt (as). We love you (Tawallah) and dissociate (Tabarrah) from your enemy. We want that so that we may save ourselves from the Fire."

Then, the man became weak, and began to weep. So Imam as-Sadiq (as) said, "Ask me, for by Allah, you will not ask me about a thing except that I will inform you about it."

The man said, "Inform me about the two men (referring to Abu Bakr & Umar)."

The Imam (as) replied, "They oppressed our rights, which are in the Book of Allah, and they prevented Fatima (sa) from her inheritance from her father. Their oppression has continued until today" - then he pointed to his back - "and they have hid the Book of Allah behind their backs."

[Source: al-Kafi, Vol. 8. Pg. 102]

Hadith 2:

عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنْ حَنَانِ بْنِ سَدِيرٍ وَ مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ مُحَمَّدِ بْنِ إِسْمَاعِيلَ عَنْ حَنَانِ بْنِ سَدِيرٍ عَنْ أَبِيهِ قَالَ سَأَلْتُ أَبَا جَعْفَرٍ (عليه السلام) عَنْهُمَا فَقَالَ يَا أَبَا الْفَضْلِ مَا تَسْأَلُنِي عَنْهُمَا فَوَ اللَّهِ مَا مَاتَ مِنَّا مَيِّتٌ قَطُّ إِلَّا سَاخِطاً عَلَيْهِمَا وَ مَا مِنَّا الْيَوْمَ إِلَّا سَاخِطاً عَلَيْهِمَا يُوصِي بِذَلِكَ الْكَبِيرُ مِنَّا الصَّغِيرَ

Narrated as part of a hadith with a reliable chain of narrators that Abu Jafar Imam Baqir (عليه السلام) was asked about the two of them (i.e., Abu Bakr & Umar),

Imam (عليه السلام) responded saying, "O Abu Al-Fazl, don’t ask me about these two, for by Allah (عز وجل), no one from among Us has died but that they are angry against these two, and there is none from Us today but that He is angry with them. The elder ones from Us make this as a will/recommendation/command (Wasiyat) to the young ones."

(partial hadith quoted here)

[Source: al-Kafi, Vol. 8, Hadith. 340]

Hadith 3:

وَعَنْهُ عَنِ الْفُضَيْلِ عَنْ أَبِي جَعْفَرٍ عليه‌السلام قَالَ إِنَّ فُلَاناً وَفُلَاناً ظَلَمَانَا حَقَّنَا وَقَسَمَاهُ بَيْنَهُمْ فَرَضُوا بِذَلِكَ مِنْهُمَا وَإِنَّ عُثْمَانَ لَمَّا مَنَعَهُمْ وَاسْتَأْثَرَ عَلَيْهِمْ غَضِبُوا لِأَنْفُسِهِمْ

Narrated that Abu Jafar Imam Baqir (عليه السلام) said,

"Fulan & Fulan (i.e. Abu Bakr & Umar) wronged Us, they took what was rightfully Ours and both of them divided it between them and they (the Muslim community) were satisfied in getting that from both of them. And then when Uthman held it back from them and took it exclusively for himself, they (the Muslim community) became angry for their own sake."

[Source: Kitab al-Sarair, ibn Idrees al-Hilli, Vol. 3, Pg. 549]

Shaikh Mahmood al-Amili al-Shahabi in his book Saheeh al-Amili after authenticating the hadith comments on it:

أقول: وفي هذا الخبر لوم شديد وعتب صريح على كل الأمة حيث سكنت ورضيت وهم يرون آل محمد يُظلمون ويُهضم حقهم، ولم يسكنوا بل تحركوا وغضبوا أن رأوا عثمان قد استأثر عليهم ببعض المال والسلطان، فكان بعض المال والسلطان عند هذه الأمة الجاهلة أعظم شأنا من حق محمد وآل محمد (صلوات الله عليهم أجمعين)، وهذا قمة الجهل وقمة تعظيم الدنيا والاستخفاف بشأن الله تعالى ورسوله (صلى الله عليه وآله)

"In this report, there is severe blame and clear/open criticism on the entire (Muslim) nation that stayed calm and remained satisfied, while they saw the family of Muhammad (صلى الله عليه وآله) being oppressed and their rights being violated. And on the other hand, they did not remain calm, but arose and became angry when they saw that Uthman had gained some wealth and power exclusively for himself over them. To this ignorant nation, some wealth and power held greater importance than the rights of Muhammad and his family (صلوات الله عليهم أجمعين). This is the height of ignorance and the height of glorifying the world while belittling Allah and His Messenger (صلى الله عليه وآله)."

[Source: Saheeh al-Amili, Vol. 3, Pg. 192]

Hadith 4:

Narrated that Imam Ali (عليه السلام) while explaining the wrongdoing of Abu Bakr & Umar said the following:

ثم قال عليه السلام: العجب مما أشربت قلوب هذه الأمة من حب هذا الرجل وصاحبه من قبله

"It is surprising how the hearts of this nation are filled with love for this man (Umar) and his companion before him (Abu Bakr)."

فمساويه ومساوي صاحبه أكثر من أن تحصى أو تعد، ثم لم ينقصهم ذلك عند الجهال والعامة، وهما أحب إليهم من آبائهم وأمهاتهم وأنفسهم، ويبغضون لهما ما لا يبغضون لرسول الله صلى الله عليه وآله

"His (Umar’s) faults and the faults of his companion (Abu Bakr) are more than can be counted or enumerated, and that did not reduce them in the eyes of the ignorant and the common people, and those two are dearer to them than their fathers, mothers, and themselves, and they hate for those two what they do not hate for the Messenger of Allah (صلى الله عليه وآله)."

[Source: Kitab Sulaym, Hadith. 14, Pg. 224 & 234]

Hadith 5 - The 3 cowards:

Narrated that Imam Ali (عليه السلام) said the following about the 3 before him:

وأنه ليس رجل من الثلاثة له سابقة مع رسول الله صلى الله عليه وآله ولا عناء معه في جميع مشاهده، فلا رمى بسهم ولا طعن برمح ولا ضرب بسيف جبنا ولؤما ورغبة في البقاء

"And surely none of those 3 had any precedence/preference with the Messenger of Allah (صلى الله عليه وآله) and did not share any hardship with Him in all his battles. Neither did they shoot an arrow, nor stab with a spear, nor struck with a sword due to cowardice, meanness & desire to live."

[Source: Kitab Sulaym, Hadith. 15, Pg. 248]