The World Federation One Stop Fiqh

Ruling 1765

If a muʿtakif dies in the middle of an iʿtikāf that has become obligatory on account of a vow, oath, covenant, or the passing of two days of iʿtikāf, it is not obligatory for his guardian (walī) (i.e. the eldest son) to make up the qaḍāʾ iʿtikāf, although the recommended precaution is that a qaḍāʾ iʿtikāf of a deceased person should be performed. Of course, in the event that a muʿtakif had stipulated in his will that in such a case someone must be hired from the one-third of his estate14 to perform iʿtikāf for him, then the deceased muʿtakif’s will must be followed.

This refers to the maximum amount of one’s estate over which he has discretion in a will for it to be disposed of in accordance with his wishes after his death.