Is it permissible to demand of the deceased husband's father a maintenance allowance for the daughters and the payment of the wife's deferred dower, knowing that the deceased left no money and was in debt?

The jurists differed concerning the maintenance of an orphan who has no wealth. Imam Shafi'i held the view that his maintenance is incumbent upon his wealthy mother, while Imam Ahmad was of the opinion that it is incumbent upon his heirs, according to their share of inheritance. The majority of jurists, relying on the verse, "And upon the heir is the like of that," held the view that the maintenance of relatives is obligatory. Accordingly, the mother has the right to demand from the husband's father his share of the daughters' maintenance. As for the deferred dower (mu'akhkhar as-sadaq), it is a debt owed by the husband, payable from his estate upon his death. If he leaves no estate, it remains a debt upon him (in his accountability). It is commendable for his relatives to pay it on his behalf, and for the wife to forgive it.