What is the ruling on a person in i'tikaf (spiritual retreat in the mosque) leaving the Sacred Mosque to perform 'Umrah (the lesser pilgrimage) or other things?

Answer : It is not permissible for the person in i'tikaf to leave his i'tikaf to perform 'Umrah for himself or for someone else. If the i'tikaf is obligatory by virtue of a vow, then leaving is forbidden and not permissible. If the i'tikaf is not vowed and is merely voluntary, then leaving is not forbidden, but it is not recommended. However, if he leaves, the i'tikaf becomes invalid and its end is disconnected from its beginning. The man would have only i'tikafed for five of the last ten days, and he would have invalidated them—meaning he invalidated their continuity with the last five days. It is not permissible for a person to take the signs of Allah in mockery by i'tikafing and then leaving for 'Umrah, or for worldly affairs, or the like.