The World Federation One Stop Fiqh

Ruling 1575

If a fasting person intentionally ascribes something false to Allah, Prophet Muḥammad (Ṣ), or the Twelve Imams (ʿA) – whether he does this verbally, in writing, or by making a sign and suchlike – and even if he immediately says ‘I have lied’ or he repents, then based on obligatory precaution his fast is invalid. The same applies, based on recommended precaution, to ascribing something false to Her Eminence [Fāṭimah] al-Zahrāʾ (ʿA) and to the other Prophets and their successors.