What is the ruling on paying a financial deposit in exchange for a reduction in the monthly rent of a house?

If the advance payment is to be returned to you at the end of the period, and the landlord reduces the rent in exchange for benefiting from that amount, then this is an interest-based loan (riba); because it is a loan that draws a benefit, and every loan that draws a benefit is usury (riba) by the consensus of the jurists. Usury is among the major sins, and its perpetrator is threatened with war from Allah Almighty.