original: Muslims performing i'tikaf are required to stay within the mosque for ten consecutive days, often in worship or learning about Islam.
simplifications: Muslims performing i'tikaf have to stay in the mosque for ten consecutive days.  They are in worship or learning about Islam. Muslims doing i'tikaf have to stay in the mosque for ten days worshiping or learning about Islam. Muslims are required to stay in the mosque for ten days in worship or learning about Islam. Muslims performing i'tikaf are required to stay within the mosque for ten consecutive days. They worship or learn about Islam. Muslims performing i'tikaf must stay within the mosque for ten days in a row. Time is often spent in worship or learning about Islam. Muslims doing i'tikaf have to stay in the mosque for ten days, one after the next, often praying or learning about Islam. Muslims performing i'tikaf must stay in the mosque for ten days in a row. Muslims performing i'tikaf must stay in the mosque for ten straight days. During this time, they often worship or learn about Islam. Muslims performing i'tikaf have to stay within the mosque for ten consecutive days.During this time they worship or learn about Islam. Muslims performing i'tikaf are expected to stay within the mosque for ten straight days, often in worship or learning about Islam.