Spiritual Retreat: Things That Invalidate Iʿtikaf and Its Location

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 1727

While a muʿtakif is fasting – i.e. from the time of ṣubḥ prayers until the time of maghrib prayers – everything that invalidates (i.e. makes bāṭil) a fast also invalidates iʿtikāf. Therefore, a muʿtakif must refrain from intentionally (ʿamdan) doing the things that invalidate a fast.[¹]

vi. Iʿtikāf must be performed in one of ‘the four mosques’ or a jāmiʿ mosque.

-Ayatullah Sistani, Practical Laws of Islam, Spiritual Retreat (Iʿtikāf)

1. See Ruling 1551 for a list of things that invalidate a fast.