The Shi’a scholars the Imami scholars and even the Zaydis and Ismailis have all spoken on this incident, and the Ijma’ of Shi’a on a matter reveals that it is from the Ahlul Bayt, just as in the case of reciting Bismalah loudly or Hayy ‘Ala Khayr al ‘Amal in the call to prayer.
Even if one doesn’t grant that the ijma of the Shia scholars is enough to prove that Ahlul Bayt (AS) believed in Fatimiyya, what this ijma would at the very least prove is that the belief in Fatimiyya is an early belief .
THE WORDS ZAYDI, ISMAILI AND NUSAYRI SCHOLARS
1. Abu Abdallah al-Shi'i (Ismaili d.298H)
The following statement is of Abu Abdallah al-Shi’a who said: “'You treat the person who stole the clothes from you with a value of two dinars as a wrongdoer and yet you desist in regard to someone who violated the religion of God, repudiated the Sunnah of the Apostle of God, assumed power of the friend of God, tore aside the veil of Fatima (as), daughter of God's Apostle, canceled her inheritance, took away what was in her hands as a gift from her father, murdered her, killed the infant of hers in her womb, and did many things of this kind and incited other to do so.'
Ref : Tathbit al Imamah
2. Yahya b. al-Hussain b. al-Qasim al-Hadi (Zaydi d.298H)
“Abu Bakr said to Omar, gather a group and break the door of this man (Ali b. Abi Talib), so Omar and those who were with him stood up to the door of Ali AS and they struck the door. Fatima a.s. defended the door but he (Omar) pushed her and she fell to the ground. Fatima a.s. pleaded to Umar to not enter the door for her hair is uncovered, Omar replied “Take your thawb (dress) for I am entering”. Fatima AS pleaded once more so he (Omar) pushed her and entered with his companions. She stood up between them and the Bayt (room) that Ali a.s. was in, while she saw that her rights upon them held priority over the rights of Ali a.s. over them due to her weakness and closeness to the Prophet SAWA, so Khalid b. al-Walid rushed to her and hit her with a whip on her upper arm and she cried in pain from that, and then al-Zubayr came out with his sword, and Abdullah b. Abi Bay’ah took the sword from al-Zubayr’s hands and hit it until it broke, so they then entered and forcefully brought out Ali a.s. until he gave bay’ah to Abu Bakr”
Ref : Tathbit al Imamah
3. al-Khasibi (Nusayri d.334)
al-Khasibi accounts that Al-Mufadhal ibn Umar in a long narration from Imam Al-Sadiq (a.s) in which Imam (a.s) cried said "O Mufadhal, if I tell you how much reward there is for an eye which cries, we would wish to cry blood if possible." Then Mufadhal cried for a long time and said: "O son of the Messenger of Allah (saw)! Verily the day of your revenge is greater than the day of your affliction." Then Al-Sadiq (a.s) said: "But not like the day of our affliction in Karbala, even though the day of Saqifah and the burning of the door over the Commander of the Faithful (a.s) and Faatima (s.a), Al-Hassan (a.s), Al-Hussain (a.s), Al-Zaynab (a.s), Umm Kulthum (a.s) and Fidha (r.a). And the murder of Al-Mohsin (a.s) was caused by a kick which resulted in his death, that day was greater for us, because that is the source of afflictions.".
Ref : Al-Hidaya Al-Kubra page 407
4. Abul Qasim Al Kufi (Ghali d.352)
Abul Qasim Al Kufi says the following:
“Then they both (i.e. Aboo Bakr and Umar) asked for allegiance and rulership over Muslims, without any covenant from Allah (swt) or His Messenger (saw) about it. And also they attacked the house of Fatima (s.a) the daughter of the Messenger of Allah (saw), violating her honour by forcing her to come out after her husband, whom they dragged to the mosque to force him to pay allegiance and he denied it, and Abu Bakr ordered his cousin Qunfudh to beat her, and Umar pressed her between the door and the wall until she miscarried Mohsin (a.s).”
Ref : Istighasa V2,Page 77
5. al-Qadhi al-Nu’man (Ismaili d.363H)
Qadhi Numan says the following poem:
“…Umar came to them with a group, Seeing the man they installed was not obeyed, Till they reached the door of Fatima,The Batul lady who boycotted them. She intercepted between him and them, Hoping they would not reach her man, But he broke the door, the first such insan, And they forced their way through her veil, As she did cry, ask for help and wail., They hit her, so she did miscarry, Al-Zubayr heard the call and went in a hurry, But stumbled, his sword was taken, And was surely by them broken, So they caught al-Zubayr and he, In their hands a captive came to be. The wasi came out with the rest of the men, Seeing their defenses were totally in vain. Them did they surely overpower and bringing them to ‘Ateeq in an hour. .He goes on to say: What a sigh in my heart Like fire I feel in my mind. Their killing al-Zahra’ Fatima Ignited in my insides the fire, For it is known among the people She died after having miscarried, She ordered to be at night buried, And her grave’s marks obliterated, Now nobody knows where she is buried…
Ref : Al-Urjuwazah al-Mukhtarah p79
6. Ahmad b. al-Hussain (Zaydi d.420H)
“And it is known that when Ali a.s. refused to give Bay’ah, they attacked the house of Fatima a.s., and Ammar was hit, and the sword of al-Zubayr was broken, and Salman was ridiculed”
Ref : Sharh al-Usul al-Khama with Ta’liq of Ahmad b. al-Hussain p756