Making up for the missed Salah by the father

Q: My father died after suffering for two years from an illness that restricted his speech and movement. He was ignorant of some religious affairs, due to his old age. Is it permissible for me to offer obligatory Salah (Prayer) on his behalf? Is it permissible to give charity on his behalf from time to time? Is it permissible for me to perform Hajj or `Umrah (lesser pilgrimage) on his behalf, bearing in mind that he did both of them? To conclude, I ask for your help and guidance to the good path. May Allah prolong your life and have mercy upon you! He is All-Hearer and Responsive. (Part No. 25; Page No. 257

A: If your father used to lose his consciousness during his sickness and could not distinguish anything, then he would be exempted from Salah, for he was then not Mukallaf (person meeting the conditions to be held legally accountable for their actions) because responsibility for Salah depends on consciousness, which is lacking in this particular case. However, if he did not lose his consciousness or reason, but left Salah out of ignorance of its obligation on him according to his ability, even in case of illness, we hope that Allah will forgive him and excuse him for his ignorance and lack of people who could clarify the Shari`ah ruling for him until his death. May Allah forgive him and have mercy upon him! In both cases, it is not permissible for you to offer Salah on behalf of your father, for no one is permitted to offer Salah on behalf of another. The basic principle regarding Salah is that it cannot be performed on behalf of others. As for performing Hajj and `Umrah on behalf of your father, this comes under having kindness and compassion upon him. You should occasionally give charity on his behalf, supplicate to Allah for him, ask Allah's Forgiveness for him, join his ties of kinship and visit his friends and be kind to them, for all this comes under having dutifulness to your father after his death. You shall be rewarded greatly In sha’a-Allah (if Allah wills) for doing this.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.