I heard that supplicating for others is an expiation for them, especially by mentioning their names, as it protects them from Hellfire and grants them good deeds. I supplicate for a Christian woman who loved God and dedicate the reward of reciting the Qur’an to her. Will this protect her from the torment of the grave and Hellfire? And how do we dedicate the reward of prayer to someone or perform a prayer specifically in their name, and what do we say before starting?

All praise is due to Allah.

The religious texts have clarified that the deceased benefits from certain good deeds performed by the living, namely: supplication for them, giving charity on their behalf, performing the obligatory Hajj and fasting on their behalf, and repaying their debts.

As for dedicating the reward of acts of worship for which there is no textual evidence, such as prayer and reciting the Quran, scholars have differed between those who permit it and those who forbid it.

It is better for a Muslim to perform acts of worship for themselves and to supplicate for their deceased Muslim brethren.

It is not permissible to seek forgiveness for or dedicate the reward of good deeds to deceased Christians, because Allah has forbidden seeking forgiveness for polytheists, and this will not benefit them as long as they died upon a religion other than Islam.