Is money obtained from financing furniture through Islamic Murabaha, then received in cash instead of furniture to pay off debts, considered illicit money?

This transaction requires knowledge of the details of its execution to rule on it. However, if the questioner is cooperating with the furniture company through prior collusion to take the price of the furniture, not the furniture itself, then this makes the transaction akin to obtaining an interest-based loan. This is further confirmed if the price the bank will pay to the company is greater than the price the company will pay to the questioner.

The known method for obtaining money is through Tawarruq, not Murabaha sale.

The questioner should seek Allah's forgiveness frequently and resolve not to return to such transactions until their ruling becomes clear to him.