Is the furniture and furnishings received from the money of a father who dealt in bribery considered unlawful (haram)? And is there a way to purify these possessions? What must the children and wife do if they know that the father's money is unlawful? And what is the ruling on the small amount of money that is now being received from him through the judiciary?

There is no harm in eating with or dealing with someone whose money is mixed with lawful and unlawful earnings, although it is more prudent to abstain. As long as your father has lawful earnings from his job (salary), mixed with bribery, there is no harm upon you in taking furniture, furnishings, or the maintenance he provides, because you are taking money from him as it is your right, and there is no sin upon you in benefiting from that.