Is it permissible to consider the money given to the mother and sisters residing in the home as expiation (kaffarah) for the deceased father, knowing that it is paid from the married giver's personal salary and in installments?

If the expiation (kaffarah) is obligatory upon the father, it should be disbursed from his estate before its division. If he has no wealth, it is commendable for the children to pay it on his behalf, as a debt owed to Allah is more deserving of fulfillment.

It is not permissible to consider the amount paid to the mother and sisters as expiation, because the recipients of expiation are the poor and the needy, not those whose maintenance is obligatory upon the payer or who are voluntarily supported by him. Furthermore, the maintenance of the mother may be obligatory, and the maintenance of sisters is sometimes obligatory according to the Hanbalis. Even if the maintenance is not obligatory, it is not permissible to consider it as expiation as long as it would cut off what was previously given voluntarily.

As for paying the expiation in installments, it is permissible if it is held that immediate payment is not obligatory. However, if immediate payment is deemed obligatory, then it is not permissible to pay it in installments without a valid excuse.