We owe money to the bank as we had taken mortgage for our home. We want to sell some property, a house in which family members were living. These family members are not now in need of that house. We want to sell that house and pay that amount towards our mortgage .
My question is that , do we have to pay Khumus on that money. After paying this money to the bank towards our mortgage, still we will be owing some money but the only relief will be that some of our burden will become lighter.

If you immediately your mortgage before your khums date, khums wont be applicable.