What is the ruling on the money that a father spends on his family, if the source of his money comes from working on a truck that he bought through a usurious bank and by usurious means? And what is the ruling on the food and drink of those in the family who cannot support themselves except from this money?

The sanctity of money is connected to the liability of its taker, not to the money itself. Therefore, there is no harm for you in benefiting from what your father earns from his work in a car he bought with a usurious loan. The prohibition of a usurious loan is connected to his liability, and he must repent from it by feeling remorse, seeking forgiveness, and resolving not to return to it. He should also hasten to repay the debt if that would relieve him of theurious interest.