of other days, as Allah the Exalted says, “then an equal number of other days” (al-Baqarah 2:184). This ruling applies when recovery is hoped for, or when the illness lightens at certain times.
But if the sickness is ongoing and chronic, with no prospect of cure, then feeding the poor becomes obligatory, for Allah the Most High says, “And upon those who are able to do it [only with hardship] is a fidya: feeding a poor person” (al-Baqarah 2:184). The chronically ill person is included in this verse.
The fidya is not to be given in money, as you mentioned. Rather, it must be given as food—specifically, the staple food of the country. For each missed day you are to give half a sāʿ of that staple; half a sāʿ is approximately one and a half kilograms. Therefore, for every day you must provide food in the stated amount, and you must not give cash instead, because Allah, Glorified be He, says, “And upon those who are able to do it is a fidya: feeding a poor person” (al-Baqarah 2:184), explicitly mentioning food.
Question: For the days on which he paid cash, is he required to repeat the fidya and give food instead?
Answer: If a qualified scholar issued him that legal opinion and he was satisfied with it, he is not obliged to repeat it. However, if he acted on his own initiative, or was not convinced by the fatwa he received, then he must repeat it and give food.
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Question: Last Ramadan I suffered some pains and was unable to fast, so I broke the fast, and I compelled my wife—who was accompanying me during treatment—to break her fast as well. Now I wish to offer food as fidya because I am still unable to fast,