3. Intentionally letting the thick dust or smoke enter the throat.
Therefore, smoking invalidates the fast.
What about nicotine patch?
Since this is not administered through the mouth, it does not harm the fast.
4. Vomiting intentionally (even if it is for a medical purpose).
5. Submerging the head completely into the water.1
6. Sexual intercourse.
7. Intentionally remaining in state of janabat2 till the time of fajr (dawn).
A person becomes junub & then goes to sleep without doing the ghusl:
a) with intention of not doing ghusl before dawn = fast is invalid.
b) with intention of doing ghusl before dawn:
i. but did not wake up before dawn = fast is okay.
ii. woke up once & went back to sleep till fajr = fast + do qaza. 3
iii. woke up twice & went back to sleep till fajr
= fast + do qaza + it is recommended to pay kaffara.4
Similarly, intentionally remaining in state of hayz (period) for a woman whose bleeding has stopped and has enough time to do ghusl or tayammum before fajr.
8. Doing anything that would cause discharge of semen.
9. Using liquid enema.
10. Kizb (lying) of the highest type —falsely attributing a statement to Allah, the Prophets, and the Imams— makes the fast invalid.
Remember that these actions only make the fast invalid (batil) if they are done knowingly and intentionally. But if it is done unknowingly or by mistake, then the fast is still valid.
- 1. According to Ayatullah Sistani, submerging the head into the water is strongly disliked but not forbidden.
- 2. Junub means the person on whom ghusl-e janabah becomes obligatory.
- 3. Qaza means to make up the fast during other days after Ramadhan.
- 4. Kaffara means penalty. See the chart of “Qaza, Fidya & Kaffara.”