What is the method for settling the debt of a deceased father, the amount and creditors of which are unknown, and which appeared in a dream where he was demanding its repayment? And is it possible that the debt being demanded in the dream is the deficit in the amount given to the two sisters from the father's inheritance?

A Muslim often supplicates for their deceased parent for mercy and forgiveness, gives charity on their behalf, and dedicates the reward of good deeds to them, based on the Prophet's (peace be upon him) saying: "When a person dies, all their deeds cease except for three: a continuous charity, knowledge from which benefit is gained, or a righteous child who supplicates for them with good."

You must pay off the debts your father had before his death and search for anyone who had rights against him so you can fulfill them on his behalf. This can be announced in mosques or through media outlets.

As for the reduction in the sisters' share, it is not a debt owed by the father, but rather the responsibility of whoever distributed the inheritance after his death.