What is the ruling on a mother's mistreatment of the paternal grandmother (the husband's mother), her disrespect, humiliation, and depriving her of eating with the family, under the claim that she wants to take revenge on her, despite the fact that the grandmother has become old and has changed for the better?

Part of a wife's good companionship with her husband is her kindness to his family and her assistance to him in honoring his parents. Abusing the husband's mother is considered bad companionship, for the Shari'ah (Islamic law) commanded kindness to people, and kindness to people is among the best acts of righteousness, causes for the forgiveness of sins, and the tipping of the scales (of good deeds). The Prophet, peace and blessings be upon him, said: "Nothing is placed on the Scale that is heavier than good character."

Furthermore, whoever does good to others should intend to please Allah, and should not remind them of it or harm them. Allah Almighty said: "O you who have believed, do not invalidate your charities with reminders [of your generosity] or [other] injury." Therefore, you must be kind to your grandmother, honor her, serve her, and be her companion. You should advise your mother by explaining the error of her ill-treatment of your grandmother and the virtue of being kind to her, while observing the appropriate manner of addressing parents.