What is the religious ruling on a husband who is known for his good character outside his home, yet inside it he mistreats his family and frequently swears to divorce, despite being diligent in prayer and memorizing the Quran?

It is advisable to treat the father as Allah has commanded, for his bad character does not justify neglecting his rights. Allah has commanded us to be grateful to them (parents), to treat them with kindness, and to accompany them in goodness, even if they strive to make their children commit shirk (definition) (polytheism). Allah Almighty says: "And We have enjoined upon man [care] for his parents... Be grateful to Me and to your parents" and "So do not say to them [anything that indicates] disapproval and do not reprimand them." The father has a responsibility to raise his children, and he must avoid oaths of divorce. Children must advise their father gently, and righteous people should mediate for this.