3. Obligatory fasts are as follows:
– Fast during the month of Ramadan;
– Qaḍā’ fast;
– Kaffārah fast;
– Parents’ qaḍā’ fast;
– Mustaḥabb fast which became obligatory due to nadhr, ‘promise’, or ‘swear’;
– Fast on the third day of i’tikāf
– Fast instead of slaughtering in tamattu’ haj * .
* If a pilgrim is not able to slaughter and cannot borrow money, he should, instead, fast for ten days, of which three days is kept during haj and seven days in his waṭan.
Source: Hadana adopted from the Istiftaat of the Grand Ayatollah Khamenei