Is it permissible for me to take a sum of money from my father that he deposits in the bank in my name, knowing that I am aware that interest on bank deposits is unlawful? What is the ruling on my authorizing my mother to file a lawsuit against my father for his imprisonment due to maintenance? And is the sale of one of my father's apartments considered an inheritance for me, my sister, and my brother?

Filial piety towards parents and maintaining kinship ties are obligatory, no matter how much they might mistreat or wrong you. Patience with their harm and showing kindness to them are also obligatory, as Allah the Almighty says: {But if they endeavor to make you associate with Me that of which you have no knowledge, do not obey them but accompany them in [this] world with kindness.}

Regarding depositing money in an interest-based bank: The father should be advised gently and wisely, explaining the existence of a permissible alternative in Islamic banks. If the father insists on engaging in usury, it is not permissible to take any amount from the deposit's interest, except in cases of extreme necessity to avert destruction and only to the extent that removes that necessity. If you are able to earn a living, your maintenance is not obligatory upon the father, whereas the sister's maintenance is obligatory upon him until she marries.

Regarding authorizing the mother or others in lawsuits filed against the father: If the well-off father refrains from paying the obligatory maintenance, and there is no other way to obtain the right except through litigation, then authorization is permissible. However, if the father is unable to provide maintenance or it is not obligatory upon him, then authorization would be considered aiding in injustice and disobedience.

Regarding what the father gives to some of his children from the proceeds of selling the apartment: If it is given as maintenance, then justice is achieved by giving each child what suffices them according to their needs. If it is given as a gift, the preponderant opinion is that justice is achieved through absolute equality between children, males and females alike, and that justice among children is obligatory.

As for the preachers' focus on filial disobedience towards parents rather than the rights of children, it is due to the great right of parents and the prevalence of children's disobedience, and both topics are obligatory to explain.