Ruling 1580 — Fasting (Ṣawm)

If a fasting person is asked whether the Most Noble Prophet (Ṣ) [or Allah the Exalted, or one of the Infallible Imams (ʿA)] said such and such thing and he intentionally replies ‘Yes’ when he should say ‘No’, or he intentionally replies ‘No’ when he should say ‘Yes’, then based on obligatory precaution, his fast becomes invalid.