What is the ruling on preventing heirs from their inheritance due to undutifulness to parents?

Question:
My father passed away (may Allah have mercy on him), leaving us an inheritance. We are three sons from one father, and thus from another mother. Before my father’s death, he wrote a will bequeathing the inheritance to my mother and the three of us, males, with the intention of depriving our sisters of their inheritance, due to their undutifulness to him, as he used to say (may Allah have mercy on him). My father died and the matter remained in this state. What should I do? Please advise us; may Allah reward you.

Answer:
You must go to the court. Your father had no right to exclude the two daughters from the inheritance, even if he claimed they were undutiful to him. If the matter is as you described, the wealth is to be divided among you all: the wife, the three sons, and the two daughters. If there is any difficulty or dispute among you, the reference is to the court. Go to the court; in the court lies blessing and sufficiency, if Allah wills. Yes.