What is the ruling on paying expiation (kaffara) instead of making up missed fasts (qada) when there is doubt about performing the fasting and an inability to fast due to work conditions and hot weather, and what should a grandson do regarding his grandmother who never fasted Ramadan in her life?

One who doubts whether they have made up for the missed days of Ramadan fasting or not must still make them up, because the original state is that the fasting remains an obligation, and this obligation is not discharged except with certainty.

It is not permissible to substitute feeding the poor for making up the fast due to the difficulty of making it up. Rather, the make-up fast should be delayed until a time when fasting becomes easy. Feeding the poor is only for those who are continuously unable to fast, with no hope of recovery from this inability.

As for the fasting of the deceased grandmother, if she was unable to fast and make up the missed days until she passed away, then there is no fasting or feeding to be done on her behalf. However, if she was able to make up the missed days but did not do so until she passed away, then it is recommended, though not obligatory, to fast on her behalf. It is also permissible to feed the poor on her behalf, approximately 750 grams of the staple food of the country for each day.

It is recommended to frequently supplicate for the grandmother, give charity on her behalf, and dedicate the reward of good deeds to her.