What is the ruling on how to deal with a brother who wrongs his sisters in matters of inheritance by refusing to sell a property left by their father, or to buy their share from it, and insists on settling their rights through depreciating installments? And does the questioner bear a sin if he does not prevent him?

There is no sin upon you for your brother's injustice to your sisters, as long as you did not assist him or approve of his action; because of Allah's saying: "Every soul, for what it has earned, is retained," and "Every soul will be held in pledge for what it earned." And according to the Hadith: "Behold, no offender offends but against himself."

If you are able to prevent him and support your sisters, then you must do so, because supporting the oppressed is an obligation, and abandoning it is a cause for torment in the grave, as stated in the Hadith: "Indeed, you performed a prayer without purification, and you passed by an oppressed person but did not support him."

If your brother does not cease his injustice, take the matter to court to enable the heirs to claim their rights without delay, and there is no sin in that.