Spiritual Retreat: The Duration of Staying Outside the Mosque

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 1742

In cases where it is permitted for a muʿtakif to leave the mosque, he must not stay outside the mosque for longer than it is necessary for him to attend to the matter in question.

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