If an individual intends to perform a voluntary i’tikaf and then ends it before he completes it, he should make up that i’tikaf later. Some say that it is obligatory to do so.
Writing on the subject, at-Tirmizhi says: “There is a difference of opinion about a person who ends his i’tikaf before his intended time has expired.” Malik holds: “If he ends his i’tikaf [early], it is obligatory upon him to make it up. He uses as proof the hadith which states that when the Prophet abandoned his i’tikaf, he made it up during the following month of Shawwal.” Ash-Shaf’i states: “If he did not vow to perform i’tikaf or he did not make it obligatory upon himself, and then he left it early, he does not have to make it up unless he chooses to do so.” He continues: “One does not have to undertake this act. If he did and then left it, he need not make it up [since it was voluntary], except for the case of hajj and ‘umrah.” Notwithstanding this, the imams agree that if one makes a vow to perform i’tikaf for a day or a number of days and then voids his i’tikaf, it is obligatory upon him to make it up whenever he can. If he dies before he makes it up, then no one is obliged to make it up on his behalf. On the other hand, Ahmad argues: “It is obligatory on his inheritors to make it up on his behalf. ‘Abdurrazzaq related from ‘Abdulkarim ibn Umayyah who said he heard ‘Abdullah ibn ‘Abdullah ibn ‘Utbah say: “Our mother died while she still had some i’tikaf to perform. I asked Ibn ‘Abbas and he said: ‘Perform i’tikaf on her behalf and fast.'” Sa’id ibn Mansur recorded that ‘Aishah performed i’tikaf on behalf of her brother after his death.