This Is My Faith - Al-fatlawi, Ali - الصفحة ١٥٧ - Including Infallibility (‘Isma)
type of infallibility is restricted to Prophets and Imams (PBUT).
Deeds infallibility: is purity from committing sins or making mistakes only intentionally. Every person is capable of achieving this type of infallibility through self-restraint and righteousness. Abi-l-fazl Al-Abbas and his sister Zainab, Fatima Al-Ma’souma, Ali Al-Akbar and others (PBUT) are crystal clear examples for people who could attain deeds infallibility.
Anwar: Will you explain the process through which one attains infallibility?
Hasan: Briefly, infallibility is a high form of piety that one can obtain via absolute awareness about the consequences of committing sins and their ugliness as well as pure love for the Creator and worshipping Him. This is how one can turn away from committing sins or making mistakes.
Anwar: This was very brief, yet very beautiful and useful. However, could you please present us with evidence to the necessity of infallibility?
Hasan: As you know, proofs to infallibility are either