Question 113: I was wondering, I know that ascribing lies to Allah acc the infallible (a) breaks ones fast, but is this only if someone says it to someone else? For instance what if someone kept a journal only for himself during Ramadan and then it turned out something he wrote was incorrect, would this break his fast? What if he ascribed a lie intentionally by writing?
Jazak Allah
Answer 113: Ascribing lies to Allah (SWT) and His Prophet (pbuh) is one of the things which invalidate our fast.
If a person who is observing fast, intentionally ascribes something false to Allah, the Almighty and the Holy Prophet (pbuh) and his vicegerents (a.s.), verbally or in writing or by making a sign, his fast becomes void, even if he may at once retract and say that he has uttered a lie or may repent for it. And, as a recommended precaution, he should refrain from imputing lies to Bibi Fatema Zahra (a.s.) and all the Prophets and their successors.
If a person intentionally ascribes to Allah or the Holy Prophet or the successors of the Holy Prophet a falsehood fabricated by some other person, his fast becomes void. However, if he quotes the person who has fabricated that falsehood, his fast will not be affected.
As a result, if he wrote something false to Allah and the Holy Prophet (pbuh) while he is fasting, his fast becomes void. Otherwise, if he wrote it in other months (excluding the holy month of Ramadan or a day he is fasting), his fast doesn’t become void. He must only repent to Allah (SWT), with sincere repentance! Maybe his Lord will absolve him of his misdeeds.[1]
For further information in this regards, please refer to the following answer:
Index: Things from which a person keeping fast must abstain & Kaffarah (Expiation), answer 372.
[1] . The official website of the office of Sayyid Sistani (ha), Fasting » Ascribing lies to Allah and His Prophet.