Religious seclusion means to stay in a mosque with the intention of worshiping Allah the Almighty and growing closer to Him; it will also suffice if a person just intends to stay (and not necessarily perform worships) in a mosque to grow closer to Allah, although one should make the intention of performing the worships as a precaution.

Religious seclusion will be valid whenever fasting is valid, and the best time for that is within the last ten days of Ramadhan. Generally, secluding in a mosque for the purpose of ritual worship is a recommended act, and one may lead such seclusion on one’s own behalf or on behalf of any dead or living person; however, it is a recommended precaution to do it on behalf of living people with the hope of enjoying the heavenly rewards and blessings.