Is it permissible to benefit from the difference in the interest rate spread when selling a house to cover bank expenses, taxes, and the selling company's fees, without investing the surplus amount in the price of the new house, given the unavailability of Islamic banks and the need to sell the current house and buy a larger one using the same financing method?

Borrowing with usury is forbidden except in cases of dire necessity. Purchasing or building a house does not fall under the necessities that permit usury, as the need for housing can be met through renting. The availability of a small house that fulfills the purpose prevents engaging in usurious borrowing to buy a larger house. Similarly, usurious gains may not be used for bank expenses, taxes, or renting a house, because usury must be disposed of by spending it on general Muslim interests or for the poor and needy.