What is the value of the expiation (kaffarah) that must be paid for the salvation of the deceased, and is it permissible to pay the entire inherited amount from the deceased mother as expiation, or can the surplus exceeding the determined value of the expiation be retained?

All types of charity on behalf of parents after their death are recommended, not obligatory, and are considered an act of righteousness towards them. Righteousness towards parents after their death is achieved by praying for them, seeking forgiveness for them, fulfilling their pledges, maintaining kinship ties that are only connected through them, and honoring their friends.

When a person dies, their deeds cease except for three: a continuous charity (sadaqah (definition) jariyah), a righteous child who prays for them, or beneficial knowledge. There is no specific amount stipulated in Islamic law for charity given on behalf of the deceased.

The mother's debts must be paid first from her estate, then the remainder is to be divided among the heirs according to their prescribed legal shares. Any heir may donate their share or a part of it without a specific limit. It is better to keep some money, especially when needed, for the Prophet, peace and blessings be upon him, said: "Keep some of your wealth, for it is better for you."