Question: My grandmother (may Allaah be merciful to her) died two years ago, but she was unable to perform Sawm (Fast) in Ramadaan, as she was ill and feeble-minded. What is the ruling? Should I pay Sadaqah (voluntary charity) for each day in which she did not perform Sawm, or what should I do?
Answer: You should feed a Miskeen (needy) for each day in which she did not perform Sawm an amount of half a Saa` (1 Saa` = 3 kg. Approx.) of the staple food of the country. Ibn `Abbaas (may Allaah be pleased with him and his father) commented on the Aayah (Qur’aanic verse) in which Allaah (Exalted be He) states.. read more here.