Is it true that a son is not obligated to serve and care for his mother, and that his dutifulness to her is limited to financial support? And is it Islamically permissible for him to demand that his wife serve his mother who is unable to care for herself?

Serving parents when they are in need is an obligation upon all their children, both males and females, whether by serving them directly or by hiring someone to do so. This has been affirmed by As-Saffarini, Al-Khadimi, and the Kuwaiti Fiqh Encyclopedia. Thus, serving the grandmother is obligatory upon all her children according to their ability, and it is not limited to daughters only. Honoring one's parents is considered among the best deeds and the most beloved to Allah, and among the quickest in reward and blessing in sustenance and lifespan. Ibn Abbas, may Allah be pleased with both of them, said: "Indeed, I do not know of any deed closer to Allah, the Almighty and Glorious, than honoring one's mother."