Seerah

We can deduce her infallibility from three proofs - this is in addition to the aforementioned hadith: 'Fatimah is part of me, whoever makes her angry makes me angry':

First proof - If we study her life, from birth to death, her life with her father, husband, sons and all people, we will find no error or wrongdoing in thoughts or speech, or uncertainty in deeds; thus her life has been a manifestation of infallibility in the most comprehensive way.

Second proof - She is from the People of the House (Ahlul Bayt), whom Allah kept from all uncleanness and on whom he conferred thorough purification, and so the verse of purification includes her when it includes Ali, al-Hasan and al-Husain (as) - the verse that serves as proof of their infallibility. The verse of purification is, therefore, a witness of the truth, which cannot be disputed by falsehood, that Fatimah is infallible.

When we use the verse of purification to prove her infallibility, this does not mean at all that before the revelation of the verse she had not been infallible. Rather, she had been infallible before its revelation, with an absolute infallibility for which her conduct stands as witness. The verse of purification merely confirmed this infallibility; it did not confer it upon her.

Third proof - Fatimah al-Zahra (as) is the Doyenne of the Women of the World, as was confirmed by the famous hadith narrated by the two schools of thought. It is inconceivable that a woman would attain the position of the Doyenne of the Women of the World without being a person who lived the whole of truth in her mind and heart, and that falsehood could ever creep into any of this at all.

Adapted from the book: "Fatimah (as); a role model for men and women" by: "Sayyid Muhammad Husayn Fadlullah"